How?

Take a mold and fill it. Problem is how to process the rubber in that era to be super thinn and flexibal enough. Heat etc is hard to be exact whiout knowleage.. hes a doctor not a chemist ╮(￣▽￣)╭

Yeah bruh, I immediately went to YouTube to find tutorial for the whole process

Lmao the dedication
But yeah I kinda understand that, it's like when you suddenly need to search something on google before sleep. I need to know the answer..