I'm replacing a toilet in a 1920's house. Current rough-in is 13", bolt-holes to wall, thanks to added drywall and tiling. So a 12" rough in should work. However, there's a 6.5' high by 2.5" wide "bulkhead" running along the floor behind the toilet. leaving a 10.5" rough-in at floor level. So a toilet that uses the 12" rough-in distance all the way to the floor won't work. Suggestions?