To modernize an original radio retaining the original AM, you first have to do a complete restoration of the AM and all the mechanical parts. The original tuner is shared with the FM. Depending on what needs to be replaced, kiss $200-300 goodbye. Then after realignment of the tuner section and final testing, the small piggy-back FM board is added. It taps into the existing amplifier and part of the tuner section to give you mono FM. Your AM antenna is satisfactory for mono FM. You have the option to reuse the original face and knobs or have new reproduction ones install. It's a matter of taste.
If this is what you want then go with someone who has good experience with rebuilding AM tube radios. It's a dying art. This will narrow the field down. Then it's a matter of choosing which business offers the piggy-back board design that offers the options you want.
If you only want to play FM and nothing else, it's not logical to gut the original radio and replace with FM parts. You still have to use the mechanical parts of the old tuner and adapt it to work with the new FM tuner.
Search the Internet for "hidden stereo" for a cost effective option.
Last edited by buoymaker; 07/27/2021 4:40 PM.
