As noted. the Magnetek 6300 needs either a battery (Even a small one) or a "Battery Simulator" inorder to work (You can use a "Hardening condenser or capacitor from a high end auto-music shop think "Car Tunes" or some such)
Most other converters do not care if you have a battery or not.
Suggestions:
PAINT, two small cans (Testors?) of spray one red one black
If you have wires that run battery to battery, AND you have six volt pairs, Then skip the wire that runs positive to negative between the two sixes, But for all wires that connect ONLY to positive or ONLY to negative,, and for all wires that run off to somewhere NOT a battery.
Spray the positive wires RED, negative Black
For terminals with more than one wire attached, Tie the wires together with tape, wire ties or string.
For the POSITIVE wires, when you get them off the battery insulate them (Shove them into a plastic bag and tie it closed for example or a plastic cup inside a plastic bag is even better)
Then take your bateries to teh test center ang when you drop in the new ones,, You will know what goes where, and you won't miss a wire.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times