Thanks Dom, it can't be that difficult to replace, even though some of the foam is shaped like a circle. I'll have to get a caliper out and see how many millimeters thick it is.
I haven't used the ZC-1000 in over a decade. Hopefully it all runs well. I also hope the dirty edges on the mirror won't be in frame in the film. I've just purchased some of that Cinevia 100D Single-8 and it wasn't really that cheap.
It's funny how much a person's life can change in a decade. It feels good being able to get back into 8mm film after so much has changed.