Allegro mountain bike frame, mtb
black comb cs
I believe this is the brand, Allegro, out of Canada, 
20.5"
465 mm chain stays
135mm head tube
555 top tube
1090 wheel base
Seat post is seized in place, I couldnt seem to remove it, but didnt try heat.
Frame has surface rust. 
Would be nice to sand down and re paint, restore, if you can get the seat post out. 
Maybe a bit of heat, and penetrating oil, and work it back and forth. I would hope the seat post could come out. 
125 rear hub spacing

Designed in Canada, Made in Japan

Chomoly seamless tubing, tange, mtb, pg tubes
80's mountain bike. 

I have the forks for it too, can include them. Will try get pics.