1928 Ford Powerhouse Generator and cut out questions

[Shade Tree Mechanic]

Greetings all,

This is my first post to this group and I am hoping someone can help. I recently purchased a nice 28 Phaeton that wasn't running. I rebuilt a T over Covid, and helped a few friends with A's over the years, but this is my first Model A.

While troubleshooting - the first thing I found was that the new battery the previous owner put in had the polarity reversed (i.e. Neg ground) along with the coil polarity (Red to Neg -) . The Red wire to the key was also badly frayed, and shorting out - and the timing, points and plugs were also significantly off. After some tinkering I was able to eventually get her running.

Going down the checklist, I noticed the ammeter never showed a positive charge. (It showed Negative when lights on) Nevertheless, I'm assuming at least the Ammeter is ok.

When I returned after a short test drive the battery was down from 100% to ~90% on my charger. At that point I'm doubting the generator -

As my first test I ran it to a hi rpm, and tried disconnecting the battery Neg. post... She died instantly with a couple loud bangs (D@#$%^ OOPS!) Thankfully, after reconnecting the post, she started up fine -

In most car's I've tinkered on, when disconnecting a Battey the generator / Alternator and voltage regulator would cut in and keep the ignition running... but I'm not sure about A's. Am I way off with that test?

The next troubleshooting step was checking the output of the generator at both low and hi rpm. In both cases the voltage never changed, and it stayed at a steady 6.1vdc. (Same as the battery)

After that, I pulled the generator (Which is a period accurate 28 model A Ford Ar power house generator)... I opened it up and all looked 'ok' so I removed the cutout (Voltage regulator) and spun the generator up with a drill. Thankfully, it showed a steady climb in voltage up to 7.5 vdc... Les Andrew's book say's 7.2 is good, so, I'm thinking the generator is also ok...

That leaves the cut out switch - I opened that up and I was a bit surprised to see what looks like a DIODE instead of coils and points...

So - questions -

Any way to confirm this is a blown diode?
Can reversing battery polarity short out a cut out diode?
Any recommendations on where to get a replacement cut out for a power House Generator?

Thanks in advance for any and all your help

Marty