Thanks to a little help from someone at Brake & Equipment Warehouse in Minneapolis I finally figured out how to disassemble the 1970 1233464 metering valve. I just posted an article describing the process:
https://www.musclecarresearch.com/gm-1233464-autopsy
I'm working on a seal kit so it can be rebuilt. Does anyone know of any other cars that used this valve in addition to the Chevy and Olds applications?