In the Philco 48-1001 I'm working on, I just replaced all the "Domino" micas with Epoxy-dipped 500v micas. They all tested fine at rest, but, to quote Remo Gagji in "Casino:"
"...Why take a chance? Anyways...that's how I see it..."
LJB
PS: These "Domino" Micas are 60 years old. Plus, they control some pretty picture quality-related circuits. Time for Retirement...