Radio Testing
Bench testing will harm nothing. I use a low-power battery charger like a trickle charger for power, and a loose speaker for sound. If you just want to see if it makes noise an antenna is not necessary, but if you want to see how well it pulls in a station the antenna is needed.
Wiring may be harder to figure out, as I've seen all kinds of wire colors that all went to different functions. I'd suggest a FSM to check the wiring colors.