Ralph Mowery wrote:

I have not had a car with points in it in many years so may be way off
on the following.

Wasn't the usual thing to change out the points, condenser, plugs and a
few other things about every 10,000 miles or so back then ?

Yes.

That's really the reason this bit about using some scope to monitor/examine
the ignition system is borderline silly. It wouldn't matter if that car was
some "barn find" where it's been under a bundle of hay for the past 50 years
or a daily driver that someone was using for weekend tours of the
countryside, those parts were part of the normal maintance schedule and
should be totally replaced on a regular basis.

It would be surprising that the engine shouldn't be rebuilt every 25,000
miles as well. Most pre-WW2 cars from the 20's and 30's barely made the
10,000-12,000 mile range before needing a rebuild. Most of those didn't have
oil filters, there used to be kits to use rolls of toilet paper as a
replaceable cartridge.

The post war ones were better but no where near todays standards. Even into
the early 60's, getting into the 50~60,000 mile range was "good". Getting up
to 100,000 without a major overhaul was exceptional.

Something from 1948, if all original, would be a miracle if all it really
needed was the ignition system replaced. It's cheap enough to do and see but
wouldn't suprise me if the rings were gone, crank out of tolerance or even a
lesser job of the cam lobes in the distributor were flat.

All the tech available today isn't going to change the need of getting your
hands greasy.

-bruce