Salvaging Stamps Suffering From Oily Hinge Syndrome

The best lighter fluid is from Zippo which is still available as a liquid.

I'm not sure if it's available in Australia, though.

...absolutely, I have a can looking at me right now :)

I managed to track down some Zippo at a tobacconists in Leichhardt. No luck whatsoever. I've tried it on 10 stamps so far, all of which are supposed to have watermarks. In no case did it show me anything more than I could have seen by holding the stamp up to a bright light or against a black background - which is, in these ten cases, absolutely nothing. So despite the use of lighter fluid, I still have no idea whether any of the ten stamps have watermarks at all, let alone what the watermarks look like.

IT'S SO FRUSTRATING!!

Acetone was available from auto parts stores also. In the US and Canada by Fiberglass Evercoat Co. in litres.