Bob,
A build sheet does not seem to have come with these trucks. Also, the ID plate does not identify much more than truck size/series/GVW.
I'm with you regarding restoration of these trucks. Keeping them period correct can be a challenge, especially in finding out what is period correct. Finding parts is not too bad. There are a lot of opinions here and a lot of helpful people.
Regarding 6v vs 12v, if you are not going to add any modern accessories, the 6v is very reliable. First thing would be to get 1/0 (00) or 2/00 (00) battery cables from a big truck shop or a Tractor Supply Store and an Optima 6v battery (they are very powerful and they last a long time).
Good luck,
Tim
