Some electrical and serial # plate questions

Usually the windings are either soldered (really brazed) to the studs or have a ring terminal attached that the stud goes through before going through the insulating bushing. Just remove the nuts and washers paying attention to the position of insulating and flat washers and push the stud into the interior of the housing.

The windings may be fine just crimping a splice, but I like to solder the crimped sleeve to ensure the best continuity. So scrape or sand the enamel off the wire before crimping and then electrical solder will flow over it. The factory probably used a silver brazing process to make the connections so the joints would be able to stand more heat.

Before you fix the break, you may want to ohm the windings and compare the two as way to check their condition. Also need to check for resistance between the windings and the frame of the field, pole shoes etc.

I wouldn't waste much time looking for a 6 volt starter for the diesel. If such a thing existed, it would be a dog compared to a 12 volt or 24 volt starter. I think the factory option would have been 24 volt at the time with 12 volt starters becoming more common through the 60's.

I think parchment paper would be a reasonable substitute unless you could get actual paper insulating sheet from somewhere.

The resistance will read very low. It will depend a lot on how good a connection you make with the test probes, but the idea is to compare the two windings as accurately as possible. Not knowing a spec for the resistance you would hope that if there was damage, it would be worse in one coil than the other and you can detect it by a major difference in resistance. Since you cannot do without either coil, if there are major differences in resistance and the generator will not function properly, you should be safe in assuming the coils are one problem.

The shop here still works on starters etc, and I yeas ago i watched them reassemble a field and pole shoes. Seems like most of those windings are cloth wrapped and no paper was used.

Do you know how to check the armature with an ohm meter? Not as good as a "growler" but can pick up opens and shorts to frame

I was going to take the armature down to the shop to have them check it, turn the commutator and undercut it.

But yes please can you explain how to test the armature in my garage? I have a Feit multimeter (sadly not a Fluke...). I have a 6/12v battery charger with "start" option, and a spare 12v battery and jumper cables.

I will check the two coils tonight. I do actually have a new set of coils but I want to still use the old ones if they cut the mustard, and keep the news ones for spare. The tail leads on the new coils are stranded wire with cloth insulation, whereas the old coils just have the winding wire continuing out to the terminal studs.