Damn, just checked out Hogtunes but they don't supply anything for my old girl.
What about something like this. You could keep the plastic flap :-)
Sorry Justin cant find it , try this link these guys offer packages to allow your std controls to be used with their wiring harness
Justin. Can you post a picture of the existing installation. I see on Ebay there are many marine / waterproof replacements but are you saying they're no good until 98. There is an early model Harley radio also for sale.