I'm confused. It sounds like you had it working, but the title says problems.
What is it doing (or what is it not doing)?
Also, there are a fair amount of us who straddle boards, but you may want to put up a post at
www.allantenet.us (click on the Allante Net button below the big picture). Lots of Allante fanatics there, some with lots of knowledge.
There are a lot of parts that are not Allante-specific (drivetrain) but the radio is one part that is unique to the Allante (although the amps were used on other vehicles).
Dhussey is particularly well-versed at keeping these cars operating and he is a great source of used parts as well.
Personally, my radio worked and I was able to find a replacement belt for the cassette player. My amps were toast, so I went with an aftermarket amp and replacement speakers. I'm happy with the performance, but its more money and work.