The seller of an adjustable lever answered my question with:
"Although, there are multiple OEM part numbers for the various style bonnevilles, americas, speedmasters...the actual brake pump assembly that is fitted to each of these bikes, has remained the same. The part number differences come from the parts being made with different options, i.e. polished, chromed, adjustable, non-adjustable, etc. Regardless of the actual part number, the fitment remains that same."
I am watching an OEM lever first, but will probably order his adjustable if I don't get the OEM. His shipping is high, but even so the total is about the cost of a new OEM from a dealer and I don't have to drive 150 miles to get it.