Hello ! I've got a couple of Nikor 4x5 reels. Each came with it's "matching" tank. One is taller than it's brother, so I wonder why. Could someone tell me how tall are 120/620 reels and if they are same diameter as the 4x5 reel ? Because I suspect that I've got one 4x5 tank and one 120/620 tank. Many thanks in advance for your help ! P.S. Do you know where I can get plastic caps to close the cap in order to use the tank by inversion ?