Dutch Boy paints and National Lead were either part of the same corp or had a real good working relationship. A National Lead mine near where I grew up supplied the minerals that made Dutch Boy paints work so good.In the reference I posted earlier, page D-3, Dutch Boy 111 is 50/50 solder. If you have a hardness tester, see if the galv weld alloy is the same hardness.
You can just ship them over here.Gosh Mitty, I may have to dig out the 5 gallon bucket of auto body solder bars I grabbed way back when and get some pics for you to identify.