Dating a Petromax 829 Super Rapid?

I agree with you Martin on the basic ideas but we should not forget that these where working lights. So they would have be maintained and not considered to be a collectable.
Every tool that you don't maintain or use will get "hardened seals".

 

@WimVe Yes, but I also mean the issues clogged orifices or the filter of the preheater (due to residues in the fuel), and also the problem that you get with a full tank: either pumping very often, or even a flamethrower because only fuel, no air.