Found this one in poor condition, but except of the mica cylinder it is now restored, thanks to a parts donor that I had in the cellar for a long time. I decided not to re-paint the tank green because of the decals. Instead I just used Owatrol Marine Oil to conserve it, after removing most of the rust. The old fuel residues could be removed well with dishwasher cleaner with some pipe cleaner added, which also helped to preserve the patina, instead of using citric acid. Surprisingly, underneath all the rust on the side of the tank, there was still some paint preserved, which I found out when I went after the rust with a small stainless steel brush on the Dremel.