Excellent! This may actually work. I tinkered around a bit last evening and the cans I'm considering are just shy of 3" in diameter. Two are corn cans and the third which is the same diameter, but shorter is from a can of mandarin oranges. The corn cans have a lip for a can opener only at the top, so I left that alone and with a knife and small hammer opened up the bottoms enough to remove the corn and then used a dremel to open it up. A grinding attachment on the drill and finish up that edge. The oranges can I opened both ends with the can opener since it will be the middle section. The bottom end of the corn cans fit into the ends of the middle can so there is a slight overlap and when I solder them up it should make a better joint than edges butted up. I don't see a problem getting them soldered nice and tight. Aftet that I figure out the filler pipe and fuel line, sight gauge and vent. Total length is a hair under 12", so with a harness leather covering it should be a nice fit with enough room for fasteners. It's worth a try anyway... what's to lose? If it doesn't look good the I won't use it. Volume is 40 ounces which isn't bad. Photo is with the cans just set in place together. Thanks so much for taking the time to measure that. I'll let you know how it works out.
SB