My wheels have three pieces. 2 halves and a hub. What I'm talking about is putting a spacer between the two halves to widen the wheel itself. The only issue would be if the studs are long enough, if not get new studs. The same hub would be used so the spindle wouldn't need to be longer.
It's hard to be sure without seeing a pic of what we're taking about.
A set of "normal" vintage wheel halves don't use hubs.
On the other hand, a set of older Van K or Douglass halves did.....but normally they didn't use spacers...so without seeing what we're dealing with I can't offer an informed opinion.
Thank you.
As long as you don't go ridiculously wide with your spacer, I don't see a problem.
If you go too wide, I stand by my (and Sid's) comments about the effect of hard cornering a vintage kart on modern wide, soft tires.
And yes, you should be able to go with longer studs if needed.