Here are some pics of my Coleman 425. The only numbers I can find on the brackets for the tank are 3 7 . There's no third number anywhere to be found. Previous owner must have repainted it, but did so over the rust. I sanded off the rusty spots the best I could (I used a rotary stripper on a drill and sandpaper). I have a horrific cold, so the priming and painting will wait till I feel better. Still not sure if I'll do the tank red or gold. Originally it was gold. It's magnetic (steel?). Someone here mentioned magnetic tanks painted gold were pre-1940. If so, then maybe the 3 7 I found means 1937? Either way, I have both red and gold paint. Maybe I'll try the gold and if it looks funny, I'll do it over in red.