I had to use a second coat of the chemical stripper on the imron paint. Let it sit on there for a while till you see the paint bubble up.
You can see the thread I posted about the restoration of a similar frame herehttp://www.bikeforums.net/showthread...ht+restoration
I enjoyed the details like polishing the screw on headbadge and filling in trek logo with black paint.
Good luck and think about how someone might have painted it in 1978, I would vote for a brighter color.