OK, So, I replaced the fuel distributor, mixture control unit, presure damper and warm up regulator, but still have the same problem. If I disconnect the cold start, then I get no start.
You can hear the fuel pump running in this video,,
https://youtu.be/cHdEij5X3UM
So, maybe the fuel pump isn't delivering enough fuel, or the accumulator is stuck, or the pickup screen is blocked and restricting fuel flow.
I adjusted the mixture control unit two 360 degree turns in both directions, didn't notice any change.
The above parts were pulled from a known running 450SLC 1976.