AM radio conversion
I am still really happy with the work
Gary Tayman did on my '62 Lancer's original radio in the early-mid 1990s. He converted it to FM/AM operation with an aux input (originally for a Discman, now used with an iPod), without changing the appearance of the unit at all. The conversion parts he used at that time were rather primitive compared to what he has available to install currently, but as I say, the conversion job he did back then still works just fine. You turn on the radio and it's AM, just like it always was. Flick it off and back on, and you have FM.
Having seen what correct FM/AM for my '73 Dart go for on eBay, I am not going to buy one; I'd rather put the money towards a conversion of the AM unit in the '73, because that way I'll have an iPod plug-in and the capability to drive more than just the single speaker in the dash.
Other options are
this place (I have no experience with them, but they appear to offer a service of adding FM dial markings to converted radiosÂ…perhaps Tayman can also do it), or for a totally different approach,
this device.