toilet back clearance

Hey guys, I have a weird situation and I want to see if what I have makes sense. Old toilet flange is roughed in at around 16 inches from studs. Walls had about 1.5 to 2 inches of mud and tile so it was in reality a 14 inch rough in. There is a joist right around 10 to 12 inches. Original...

I am trying to replace an older (approx 1961) American Standard toilet but cannot find a model to fit. It is a 10" rough in but there is baseboard heat behind the toilet which takes up about 2" of would be clearance. Looking for suggestions or a good source of detail drawings of different...