Here's how I tackled the rust repair on the door and cowl of the Diamond T. Came out pretty well, I think. http://flynbrian48.wordpress.com/2010/07/16/diamond-t-rust-repair-just-the-thing-for-hot-day/
Better than my finest efforts, that's for sure! Maybe I ought to just let you tackle my '34 Ford cab... BTW, any shots of the rest of the truck? When I see "Diamond T Pickup", it really bumps up my interest!
Cool. I'd lay another bead of weld along the bottom edge of the patch, looks like it's not fully welded........to make sure any filler won't buble up.
LOL, sharp eyes. I ran out of shielding gas, and that needs to be done yet. Don't worry, it'll happen!