Are the locking rings all you need? Try making them from a coil spring the right wire diameter and radius. That should be a very simple fabrication project with an abrasive cutoff wheel in a Dremel tool. A round wire piston pin lock would be another possible source for a spring steel locking ring.

The round bushings with the grooves in them can be made and surface-hardened by any machinist worthy of the name, so the only essential original parts would be the yokes and the cross piece.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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