Back in the late '50s, when was almost a “Tween”, my Grandfather showed me how to make gaskets out of a cereal box (or other similar cardboard box), he took his finger and wet it with oil and rubbed it over the top of a carburetor body or other housing, he then turned it over, and pressed it onto the back of the cardboard like you would a “rubber stamp” and the oil left a perfect outline to cut out the gasket.
I do not remember if the cereal box was from a box of Frosted Flakes, but it sure was “Great” L o L . . .
With gasket material, he did much the same, but before lifting the item, he pressed down hard and he cut the gasket material around the housing with a sharp knife and then he lifted the housing or whatever and the oil smear (stamp) showed him where to cut out the inside of the gasket…
I’ve often used those technics over the years and I passed these methods on…
