Regarding Konrad's question, modern dope is apparently entirely compatible with old dope, nitrate or butyrate. At least, I have patched up 35 year-old airplanes using modern dope. The thinners used may vary since they have several components. I've been using dope a long time without noticing any change or problems. If the plane is old enough you can even put nitrate on top of butyrate, which I have done. I think nitrate sticks a little better, so that's what I put down first, then the butyrate.

I think what you are referring to is Aero Gloss, which was different from other dopes and got reformulated at some point. Maybe others can comment on that.

Jim