[69L72RS]

The pictured plates would be for a GM "trans-am" unit with 400# or larger springs. They should measure 0.1562" thick and be 2.310"+/-0.06" wide at the formed side flanges.
The COPO plates are 0.0897" thick and measure
2.100" +/- 0.06" wide at the formed side flanges.
They also have round c-clip holes not oval.

Casey,
All of the inspection docs that I have seen for the #234
COPO units begin around early 1967. They are from the Marshal division records and the signing engineers initials were D.G. / R.W. / F.R. / & R.J.S. if you know any of them.
I was told the GM made the 16 tooth axle gears in house.

I checked with Eaton in 2001 about replacement parts and was informed tooling was not avaiable and the production volume
was not worth looking at. The 16 tooth axle gears are were cut on a now obsolete Klingenberg machine while todays gear teeth are cut on a Gleason machine.

There are 2 members that I know of that have "private" stashes of NOS parts for the #234 units. I have not had much luck getting them to let go of any of it. Maybe they will decide speak up on what they have and know. Hint, hint guys.

Hope this helps. More info to follow.

Eric