Mr. Moore recommends building the chemical tanks from 35 mm film canisters wrapped with paper and topped with a balsa cap. With digital photography the norm, it's hard to find 35 mm film cans anymore, so I thought some substitution was in order. According to the plans, the tanks have a diameter of 1.25 inches. I did some searching - as it turns out, not enough - and decided to use some 1.5 inch diameter, plastic sink tail-pieces cut to the length of the tanks specified in the plans. The problem turns out that at 1.5 inches in diameter, they are too wide and will require some major changes to the catwalk dimensions, as well as some basic changes to the layout of the tank facility, to get things to fit. Overall, I think to preserve the interesting appearance of Mr. Moore's design I'm going to go back to the drawing board and find some other tubes with 1.25 inch diameters. I should have followed the old adage - which, ironically, I always preach, but apparently don't heed :-( - to "measure twice, cut once".