Cleveland wheel question. Hub thickness.

[SMRacer]

I have a 5.00-5 Cleveland 40-78B wheel with tire that I am using as a spare. A friend had a flat and I was going to loan him the wheel.
His is also a Cleveland Part No 40-78B. However when I slipped this wheel on his axel the hub on my wheel was much thinner than
the hub on his wheel. Realized this when I tried to tighten the axel nut. How can the same part number be different?

 

[rvbuilder2002]

Make certain that the aluminum spacer ring on the inner or outer side isn't missing.
It may have slid off with the original wheel and it might be missing from the one you put back on.