...Anything vintage even if narrow band FM is worthless unless gutted for 2.4. ...
If your JR or Futaba or Hitec radio takes a module, all you need to do is get an appropriate Spektrum module to plug into your radio (Fut/Hit = DM8, JR = DM9). No need to "gut" it - you can keep the old programming you're used to, and get the benefit of 2.4gHz for those events you want/need it.
Andy