Modern radio or the original AM radio?
When I got my 67 Dart in 08, the previous owner had a “Modern digital” remote control radio hanging from under the ashtray. Its “Modern” early 2000’s blinking to the tunes blue lights looked like out of date crap that hadn’t age well, clashing with the late sixties dash…
I sent the original Am Music Master radio out for reconditioning costing about 100 bucks, and was offered addition of FM, satellite, MP3 whatever for total of 200 maybe 300 bucks. Cheap me, and car’s too loud exhaust, stuck with the 100 dollar job...
For the extra money to convert original to modern guts it is still cheaper than installing a second set hidden somewhere while maintaining original for looks. And, it is a lot easier to reach the center of dash for station change than digging in glove box to access radio, or looking for its remote to operate a unit hidden in the cockpit somewhere while putt-putting down the road.