legacycentral bbs

I just bought this car, and on the way home 5th gear started popping out. I'm pretty sure it's a 5MT, and I've heard that this can be a linkage or mount related issue. What are the chances that it's an easy fix?
I haven't been able to find another 5MT at any of the local wrecking yards (us Portland residents love our Subarus!)
I can't afford a rebuild, but I have some experience repairing my own cars. Any thoughts?

There is a good chance you just need the 2 gears that make up 5th. These can be access without taking the tranny out of the car. Just the tailhousing needs to be removed. You won't need to rebuild the whole tranny.

Jeff