I had to pull my tank just to find the leak. It was behind a plastic cover on the front side and even then I had to stand the tank on it's end to see the gas almost "condensate" out. (The hole is TINY!)

I got a kit that sounds like what you used. The rest of the tank looks good, so I plan to clean the outside real good, get rid of a couple surface rust spots, and then patch and coat the tank after the patch is cured.

Thanks all for your info.