I am confident you will get a reply on this.
My general observation is that the base gasket will be thicker
because Victas did not use locating lugs on the crankcase halves -
meaning that mis-allignment was very much possible. A thicker
base gasket was the solution at design stage.
I have noticed the head gasket (and transfer ports) were made
from a different material - I guess because the mating surfaces
were better assured, and considering the higher temperature
(and pressures) encountered.
Yes, the original Victa base gaskets were thicker than the head gaskets, and different material. They were a paper/card material, but a bit better quality than a Kelloggs/Kleenex box.
The head gaskets were made of a graphited material, as were the transfer port cover gaskets. The head gaskets were a lot thinner than the base gaskets, but I have an idea that the transfer cover gaskets were a bit thicker than the head gasket - however, it's many years since I worked on one of these.
For cutting these gaskets, a standard oil-jointing gasket paper would work for the base gasket, but something better is required for the head/transfer gaskets, to handle the service temperatures. It probably won't be easy [or cheap] to find a suitable gasket sheet for these.
As these gasket sets are still readily available [including the fibre washers for the transfer port cover studs], personally I wouldn't be inclined to go chasing materials to make these. Unless you really like the challenge of sourcing obscure stuff!
