Agreed, the belt driven DC generator kit was an accessory. There is more to it than just the generator, including a voltage regulator, regulator cable, deep junction box cover, ammeter, special drive belt, and belt pulley.
If your just starting and doing occasionally running lights it will go a long long time say several weekends between charges.
These old systems are really more a charge maintainer And may struggle recharging for a sound system all day, trolling motor
or fish finder.
If you must have some of these things get a good separate deep cycle battery and charge at the end of the day.
As others have said, the parts can be found, but it probably won't be easy. I found charging system components a few years ago for my '63 Starflite, but it was a LOT of work. But at the time, I didn't mind the "hunt".
If you don't want to be bothered with all of the sleuthing and searching, then do what steelspike suggests and get an extra deep cycle battery for accessories.
