I don't have any decent part numbers for them. They are for some John Deere tractors, found them on eBay.
It's in this thread
Windshield wiper conversion Version 2.0
All my pics in that thread are gone but they are the same ones you saw in my Flickr account. I think I reposted them in a couple of different wiper threads here.
The Bronco wiper conversion kit mentioned earlier in that thread is super nice, same type motors and a fancy switch, but $100 more.