Reply to Al Letts:
Hi
I'm unsure of the answer to your question as my experience is limited to D2, but there is a lot of knowlegable folks on here that I'm sure will chime in. "Old Magnet" on the list here has compiled alot of data on direct electric starting. I'll enclose the website below. Dollars sound about right though. But pony motor repairs can be pricey as well. "Kid Nevada" on the list has a good source page for parts suppliers in the FAQ section.
OldMagnet's Electric Starter Mode
good luck
The counter weight pony was used up until sr. no. 11667 then was changed along with the magneto change from vertical mount to a low horizontal mount.
Yes, they will interchange but unless you have all the pieces to convert you will go nuts getting it mounted.
I would think the later opposed rod journal version would be the one to rebuild.
I would suggest you get hold of the parts books covering the early and later models so that you can assess what all is involved.
The direct electric start is not the easiest conversion either as there is no flange for mounting and installation starts with getting an adapter plate mounted to the bell housing. There are direct electric start conversions available ready to go but a complete installation including batteries, battery box, switches, etc. plus a generator/alternator to keep it charged will more than likely exceed that $1,000 estimate.