6 volt or 12

[1950CJD]

I purchased a project 3 weeks ago 3/4ton 1950 pickup with 235 V6 Was buried in a garage no battery just new the engine wasn't locked up. Brought it home checked the basics ,threw the only battery I had a 12 volt deep cycle battery on it small minibike fuel cell and she fired up. Ran ruff but after a few tweaks she's running great. My question is I know these trucks came in 6 volts , I can't read anything on the generator, coil. How and where do I check to see? Also there are no lights or bulbs to check and see on the truck. Sorry for the long winded ? Just wanted to give a little background info. Thanks in advance for any help!