I've got an ancient stove top espresso maker (so this is one where the water boiling is done in a pot using the stove as the heat source) and the gasket - circular - 72mm outer, 50 mm inner and about 3mm thick is farked. I cannot get a replacement as 'they' stopped making it in the 1970s. Therefore I'll have to make the gasket myself. Anyone know the spec and where I can get the sheet to cut one out? I guess it is 300 deg C rubber or silicone or something like that.