Reboring something like that headstock wouldn't be too hard with the
availability of a somewhat larger lathe. You'd just need to fasten
the headstock onto the carriage on the other lathe and use a boring
bar between centers through the bearing holes, line boring, it's
called. Getting everything lined up, shimmed up, fastened down and
the cutter protrusion adjusted before beginning is the real trick.
With the proper cutter geometry, you can end up with a very nice
surface finish and the holes on both bearings will be aligned with
each other. Whether they are aligned with the lathe bed depends on the
skill of the machinist. Takes minimal tooling but a fair amount of
skill in setting up.

You'll probably end up making a test bar anyway, no telling what it's
been through.

Stan

Exactly! I know it can be done well, but was it?? Boring it parallel
AND getting it to line up in height with the original tailstock
requires more than casual attention to detail. With a big enough
milling facilities, you could mount the whole lathe bed on the mill,
zero in on the tailstock, indicate parallelness to the bed, and bore
away.

I was surprised from the response that S.B. bored the cast iron of the
headstock for the bearings. The only lathe I had heard of that did
that was the Myford ML10 I really don't have a problem with the
concept.

At my present rate of work on the lathe, while painting the house, and
doing other things, I will probably know what the lathe is like
sometime near the end of summer. I have another old southbend, that I
use every week, with a good headstock and a bad bed that I might swap
parts with if this one is too bad.