Thank you all, and specially Bill, for the help. I can get the 2.7 oz and also 2.97 oz uncertified Dacron from Aircraft Spruce's European agent, and fiberglass in various weights locally. I will make a few tests panels and bash them when the weather is warm again. I can support that polyester peel ply is hard to remove when epoxied onto glass. It takes a visegrip pliers to get hold of the edge and a really hard pull to get it to start to come off. And that is the surface-treated true peelply. Not regular untreated Dacron which Bill uses.
Peter