I finally took old Louis' petcock apart, my new fiber washers were too small, so I got out the petcock box and found my two best used ones. I had a new Randakks 4 hole washer for a goldwing that fit, it's a dark red rubber of some sort. Anyway it's getting a test now, if it passes I'll fill the tank and put it on.
Edit; There was some rust showing on one screw, with a stain going down into the sediment bowl , this tank got a dose of water a few years ago, I acid washed it until it looked clean and lined it with northern products blue coating. It did not work, the tank is re-rusting under the coating.
It looks like old Louis is getting a different gas tank and a paint job. I'll drop the float bowls again for a quick check, if they have anything in them, I'll recover the fuel and petcock and make this bike black. I also have a set of F-B sidecovers so black is an easy option.