Sounds like you've got hug centered motor wheels and are considering using 6 lug Budd stud centered wheels, which as you say sort of fit.
I have heard of folks swapping out the studs (possibly with machine work needed) on Motor wheel style hubs for the appropriate Budd wheel studs and running stud centered Budd wheels (with correct Budd nuts), as you know they are the same bolt circle. So that's a 22.5" option. Finding a set of the ones I pictured is as well... I'd sell the one I have if interested, you'd be one wheel closer to a set.
Grigg
