Possibly made by a company that makes road frames? Mainly due to the dropout details and the top of the seat tube cluster.
Could be - ever seen one like this before?
Annoyingly the more I look at the dropouts the more familiar they seem. I'm sure I've seen something like them before.
I know exactly what you mean.
There are some elements of it that are reminiscent of my Rossin Concept MTB, but not enough for me to say that this shipped out of the same factory sadly. I had always thought that those key rear chainstay dropout details were so strikingly unique to a framebuilder or encyclopedia retro bike expert type, that they'd know what it was straightaway!
Rossin Concept MTB 1990 - Full XTR M900
Litespeed Ocoee Titanium MTB 1992 - Grafton / Bullseye / Syncros / XTR
LeMond Z Team Issue SLX 1991 - Full Corsa Record / Sigma
LeMond GAN Team Issue GLX 1993 - Full Dura Ace (7400)