Looks like the FWD distributors of the same era. That shutter wheel is attached to the plastic holder and those are notorious for loosening up int he FWD distributors. Is there any play or wiggle between the metal shutter wheel and the plastic?

I know the fix for the FWD ones was to either buy a reman or take apart the distributor and reattach the pieces more securely. In your picture there is a roll pin in the plastic collar you'd need to drive out to separate it from the shaft. To do that you'd need to pull the shaft out of the housing. There is a collar on the bottom of the shaft with another roll pin you have to remove to get it apart.

As far as I know you cannot get that wheel separately, just the pickup or the whole distributor is it for parts.