Hit up the junkyards for stock parts, sounds like alot of yours is missing or broken.
But on the bright side I just found out I'm a chump! I dont listen to stern though...where I camp there are no radio stations available.
I'm guessing your new radio has a less sensitive tuner where your old one would work ok without external antenna. I'd give you mine off the Fiero if it would fit, I don't use it just the Xm