An iconic bike!
Well I do have the rear axle for sale.
Nice to see you are interested in the Mountain Cycle brand.
But honestly, I don't fancy your chances of finding that particular frame.
Especially since Mountain Cycle now defunct.
I've been looking on ebay for a while at [any] Mountain Cycle frames; San Andreas model appears to be more popular.
And to give you an idea,
this one has 104 watchers on it.
(I'm surprised it hasn't sold already all things considered)
Why are you specifically after that model?
What is it about it that draws you to it?