Hello All.  After a few decades away from cycling, I'm becoming interested again.  There's lots of changes in bikes since the late 1990s.  I was a road cyclist and did three week long tours with large groups (1500 riders).  No longer have the road bike, but some time ago I bought a low-end MTB, a Diamondback Response Sport, hardtail w/disc brakes and 3x8 gearing. I don't use it much and now live far from mountains.  I see lots of videos showing old MTBs being "converted" to gravel bikes.  Such a bike would certainly be more appealing to me, but it seems to me that a MTB would be rather small for Gravel bike.  It also seems like I could do better by selling (or keeping) the MTB and buying a new "Gravel" bike to suit my needs.