The later model Beech Tow pin is PN:
60-820029-1. Spruce has the late model RAPCO PMA'd version for ~$25 each. I have not
found one for less.
If you find a Beech PMA Tow Pin for less, please let me know.
The hinge pin design is pictured below and is PN: 35-825106,
You do have a spare tow pin in
your plane, right?
By the way, the things that goes through the hole
in the center of them are:
MS20392-1C23 Clevis Pin and an MS24665-132 Cotter