galatron: Did you ever find your fuel leak? I just remembered something that may be helpful. About 30 years ago I worked for a short time for Kent Automotive Industries. They are a company much like 3M, but most of their sales were direct to auto manufactures and dealerships. They made a dry white powder aerosol called 'Leak Trace Powder' that dealer service mechanics and body shop guys used to find air leaks in door and window seals. If a customer complained of leaky door seal, they would spray along the seal with the door closed. The powder blow through the leak and leave a white powder residue on the seal. The mechanics used it to find fluid leaks on engines, transmissions, etc. They would clean and blow dry the suspect area with air, spray the area thoroughly with something like a can of brake cleaner, and let it dry. They would then spray the area with the Leak Trace Powder and watch for the fluid to discolor the white powder. Really simple. Below is a link to Kent's Leak Trace Powder. There may be other companies that have a similar product, but I know this stuff works. I have also seen guys take a little baby powder in the palm of their hand and just blow it onto the leaky area. I don't think that's going to work for your application.
http://www.kent-automotive.com/webapp/w ... RAY+POWDER Best of luck!