The man wants MORE caster. How about this idea?

my $.02 as an engineer with a fair amount of weld fatigue analysis under my belt, is this: the fatigue life of welds are orders of magnitude lower than the parent material. with 50 year old stamped steel parts I would not trust one that's been cut and rewelded for a street driver that you're planning on putting any significant miles on, especially with roads like we have here in MI. if you feel you have to do it, I'd probably sandwich the welded area and do a combination plug and lap weld to span the newly created gap, and then grind all imperfections in the weld bead out. that's you're best bet to maximize longevity. I'd also be inpecting them at least every fall or spring...