Seek Outside sells them in 3/4":

https://seekoutside.com/bachelor-buckles-set-of-4/

Aluminum G-hooks are a fairly new thing and so far I haven't seen any of the major buckle manufacturers take them on as a standard product. I wouldn't be surprised if it happens soon given their popularity though. We had to go searching and ended up going direct to a factory in China. Large minimum order but a good product.

Perfect. Thanks!

If you find a good source for ones that use 3/4" webbing, post up!

Search for G-hook buckles.

They are a bit hard to source in small quantities unless you find them as spares for other manufacturer's equipment.

Update on this support system:
First one shown in the above link is still going strong after many trips (roughly 2 dozen days, with a lot oftechnical singletrack). It was made for my wife's bike but I "borrowed" it on trips when she wasn't along. The first version I made was shorter and not really long enough for her bag so it sat unused, but I retrofit my bag with a support pocket and tested the shorter version on a trip the 2 of us did this weekend. Feeling lazy, I did not bother filing the conical washers that I made for her setup. I just used a flat washer and lock washer and tightened down until the tubing deformed a bit and was a bit flat (but not totally crimped). 90 miles later, with about 80% of that gravel washboard, and everything was nice and solid. No need to tighten anything along the trip.

Future versions will be raw aluminum with maybe a clear coat. Both of these versions were lightly sanded, primered and have 2 coats of paint on them, but that quickly wears when rubbing against the cordura plus getting grit between the bag and support.

First of all, go with stainless steel tubing instead of aluminum. Pack with sand or salt when bending. Flatten ends in a vice or similar and drill hole through. Heat should not be required for any of it.

Just my $.02 here: I tend to go with strength over weight for most of my parts, but aluminum tubing has been holding up just fine for over a year of use in technical terrain. It's for anti-sway, not weight bearing. Alum was cheaper and easier to work with, bending SS with a small, cheap tubing bender probably won't work.

I picked up the Ottolock specifically for trips where I don't need or want to carry a U-lock. Small, light, convenient and the design seems to be more secure than most cables

From the site description:

Security is addressed with a patent-pending, multi-layer steel and Kevlar® band design, making it extremely cut-resistant. Under load, the bands slide upon one another and effectively reduce shear forces. Conventional theft tools like wire or bolt cutters will have a hard time against OTTOLOCK. It is not a replacement for a U-Lock. For maximum security, use a redundant locking method with both a U-Lock and a secondary lock.

I posted some info on my DIY Porcelain Rocket knock-off over here:
http://www.bikepacking.net/forum/diy-make-your-own-gear-(myog)/diy-seat-pack-stabiliser/msg86667/#msg86667

Pack the tube tightly with salt before bending, it will keep from deforming. Instead of flattening the ends, I filed some adaptors. Use lockwashers on your bolts.

Tube bender was from Amazon https://www.amazon.com/gp/product/B000NPUKVQ/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Nice. 

This was my DIY solution:
http://www.bikepacking.net/forum/diy-make-your-own-gear-%28myog%29/diy-seat-pack-stabiliser/msg86667/#msg86667

How did you get a flat edge where the tube mates up to the seat collar?

I used a set of conical washer from brake pads like the ones shown below. I filed the fat washer to fit the rounded profile of the tubing of the support.

Did a custom bag for my wife with the Porcelain Rocket idea as a starting point. Instead of a holster, this is a rolltop bag with a pocket on the bottom to slip the support in. Support is 6061 aluminum tubing I bent with a pipe bender, custom filed some cantilever brake pad washers for the bolt on portion. Used a Salsa seat post clamp for her set up, used the Post-lock version when I installed on my bike which has way more seatpost showing. Will be making a new bag for myself using this set up, it is solid. Aluminum tubing was purchased from McMaster.com

Just paged through your pix, great job and nice documentation of the trip

Tuscarora Trail, the northern most part - where I'm assuming you started your journey.

A section at Big Schloss was a thorny mess a few weeks ago, I heard the Rt. 55 section was probably worse

I actually just finished an unsupported thru ride the other day, from what I can tell, potentially only the 2nd ever. It's tough, no doubt about it, but quite amazing. Let me know if anyone wants any info or pics. Bikepacking.com posted a few of them on their Facebook page today.

Nice. Was the north end off of Rt. 55 overgrown?

Been lurking on the site for a while, thought I would chime in on info I might be able to contribute to this thread.  If you like technical riding, you'll love the north end of this route. It you don't, you'll probably hate it.  I'd suggest a recon mission to see what you are getting into. It is some great riding but you'll work a lot. As you move south, things get easier. The riding around Todd Lake and the Stokesville area is great. I've done the stuff from Reddish Knob down to Douthat State Park, really beautiful riding, not as hard as the northern stuff but not easy either. I haven't been south of Douthat.

In terms of services, for the parts of the routes I've ridden, it is minimal without big detours. Water on the ridges can be hard to come by, plan accordingly. There was a camp store near Trout Run but that was closed on a Saturday at 4:30, so I would not rely on that. There is a reliable store in Stokesville and a gas station convenience store near Hankey Mountain on 250. Douthat has a small store and town is not a big detour from there.

I haven't' seen the official route other than reviewing the tracks on PedalingNowhere. Not sure what to make of this statement: "At mile 16, the correct route would go slightly north and follow a couple of trails that would connect back with 601 around mile 48". I don't see a trail 601 or route 601 on my map, I'm guessing the route probably takes Long Mountain trail which we rode this weekend, then picks up the Norther Traverse
(http://www.mtbproject.com/trail/7000106/northern-traverse).

Some photos from this past weekend's bike packing trip on the north end
https://www.flickr.com/photos/singlespeedoutlaw/sets/72157656310674760

2 weeks earlier, same area, different route.
https://www.flickr.com/photos/singlespeedoutlaw/sets/72157655707782028

If you want a sample of the riding from Stokesville to Douthat, check this video from one of SMT's tours. I was on this one, lots of fun.
https://www.youtube.com/watch?v=Xof9Xg0hQn8