[Zeke]

Yeah, smaller wire on sheet metal. You have chosen some tough areas to weld. When you can't get the gas nozzle down within a 1/2" of the work, your stick out may be too much. For the good bacon sound, get in close with the torch.

Speaking of torches, you should have a small oxy/fuel set up. When you get done grinding and find those pin holes, braze them. You could lead them too, but it takes a lot of cleaning and tinning before you can flow the solder. Brazing need to be on clean metal too, but a stainless steel wire brush will get it pretty much there.

A spot sand blaster is very handy as well for this kind of work.

You're doing an excellent job. Look for DarrylD 's posts and his web site for some really good tips on this work. He did a marvelous 912 project and documented it all.