The last I knew, Ed had re designed his new retainers to fit all the hardware.
It was too bad he forgot to check the hardware market before he finalized his design.
He and I talked, "after the fact" and he wanted me to move the groves on my hardware.
As was pointed out, that couldn't be done without a safety issue.
And yes there is a smaller, lighter weight ring that is made.
I have seen failures, with higher thrust motors using them.
As much as I would like to have helped him out with his problem, I couldn't change an established design.
The best solution is to place the snap ring on the casing, and using a bench grinder turn the casing and grind off about .01" from the OD.
This will not compromise the strength of the ring, and allows it to fit the GL old style retainers.
Maybe GL can provide a retro ring to fit the old style retainers, I will be happy to give him permission to allow customers to grind down the standard AMW/Kosdon East retainer rings, without incuring any loss of safety, if he wanted to do so.
hope that helps.
Paul