The alternators generally used are adaptions of the Delco 10SI in either 12 or 24v.

Canevari Bros. located in Woodland, CA has a repair center, part of their parts store. The fellow that does alternator/starter repairs etc. has helped many in the past with electric start conversions. Many of the local farmers use them for the starters; American International Manufacturing? used to sell the adapters for the alternators (Woodland, CA)
Mike B. here on the BB might remember who the names are. I'm getting old and suffer from CRS. JM

Yes, we conclude that at one time these came out of Woodland but I don't think there has been any conclusion on who is currently the manufacturer and is supplying Auto-Lec.

what im doing for a alternator conversion is using the factory bosch housing and gear with a new and longer shaft with a locking collar to keep it in the right spot and a vee pully on the end past the rear bearing with a bracket for a one wire alternator. the advantage of this is I can get the alternator to the "right" driven speed and have it charge correctly even from idle I simply change the driving pulley to get the right ratio. it also allows easy changing if the alternator dies and that model is no longer available etc.

That's sounds like a good design and simple enough to do thanks to all for your input.

Adwest, did you get this solved? If so, can you share how? I'm facing the same issue right now with my 17A. Talking to Auto-lec, the 371-12144 housing is no longer available. I see the MT50s listed on ebay advertised as fitting but with the incorrect helix. If those units do, indeed, mount up then the issue of machining the correct bendix is less of an issue.

Just ask the ebay seller to provide a RH Helix drive. No shortage of them.

If so, great. I guess I was more concerned about if the nose was actually the correct one for a 17a.

I reached out to a couple of the sellers on ebay for clarification but it's clear they are not versed in the various flavors of D7 and if this one was correct for a 17a.

OM, you say there's no shortage of the RH drives. I might be looking in the wrong places but can't find any in stock under the 12197 part number. I was able to source the correct starter nose but, as with adwest, it has a LH.

Call here for the 12197 starter drive....