Thanks for the replies. I just figured out that I wasn't set to "auto-subscribe" to forums that I posted on, so I'm a bit late
I was able to find a set of 7" rims at a tractor salvage yard off of an old John Deere 140? (I forget now). They puts my back tire width at 35.5", just about perfectly where I wanted them. The bonus is They came with a ratty old set of Goodyear Ags on them that actually seem to be holding air.