The two piece clamp on colllar was purchased from McMaster Carr (P/N 6436 K74). It came cut in hallf held by two screws. Each half of the collar was countersunk on the inside curve and drilled for 1/4-28 bolt.The tubing was 1/2" OD and 0.260 ID, the perfect size from Aircraft Spruce! It was cut to length to leave room for two nuts on the end of each screw (MS24694-S119 machine screw). One nut to hold it and the second to lock it with a touch of Loctite. The tow bar piece was installed on the 1 1/4" front strut. I had planned to use 0.025 aluminum shims if the tow bar piece was too loose. No need. It pulled up tight!
