Get one from Joe then, and if he doesn't require a "core" then you can fix
the old one at your leisure. I've had a couple end plates welded and redrilled
with good results.
The field windings are connected in series so checking from the outboard leads
of the pair will show you if both are good. (One end is probably connected
to ground - you'll have to disconnect that from ground before testing for
shorts to ground.) Also check between the leads and
ground with resistance set on high range to determine if you have a short to
ground. If you don't have continuity through the two in series, connect your
test lead to the wire in the middle and check both of them. The one that
doesn't show continuity needs to be fixed (break found, wires soldered together
and insulated to avoid shorts) This is a bit tedious but not complex.
--
George Downs, Bartlesville, Oklahoma, Central US