1976 MCI Bus Tire RIM size

[DirtDiver]

I have a 1976 I believe MCI-8 with 12r22.5.  I had someone steal my tag tires.  I had a spare but now need an aluminum rim for the 2nd one.  There are 10 lug nut holes.  On a tape between 8-9.5 inches wide where the tire meets the rim.  I want to make sure I get the right one.  on the inside it says Alcoa on the rim.  Suggestions?  I searched rim size on the threads and could not find it.