Richard,
Unfortunately I can't find any record of the senders I bought so no part number i'm afraid, however I have done some research again and tracked the supplier I used to Tri Starr Radiators, 1452 State Rt.89, Seneca Falls, NY, 13148, USA. tristarrradiator.com - email
sendingunitguy@gmail.com
The guy I dealt with is Dan O'Hora who remembers me and thinks the senders I had were King Seeley units. If you were to email him a picture of your senders he will be able to confirm that. The ones I have work well and are almost identical to the originals, just be aware that the float arm is central on the new ones where they are offset to one side on the originals so you have to bend a 1" offset into the arm to get it to pass through the slot in the fuel tank baffle.