I have note used this company myself, but I have done some research on it a bit lately. This company takes old am radios and converts them to 180 watt am/fm radios. The cost is a bit pricey, but you keep the vintage look. I e-mailed the guy and he told me like $385-400.
http://www.turnswitch.com/radio1.htm
BTY, they take in old radios and refurb/upgrade with new electronics.
Hope this helps,
Adam