When I restuff these I pot them with thermally conductive epoxy. Therefore they cool the same as the originals, maybe better. With the lower ESR of modern parts, the caps have a hair less heat coming off of them. A red hair though!
Funny you should ask . The 2285B doesnt use vellum but I've another Marantz sitting waiting it's turn that does . So yes, I could use a sheet .. if you dont mind sharing.