Unfortunately the way Pacemaker Crown Graphics are constructed there's a plate in the back which is rectangular and would prevent a rotating back being used in portrait mode as it obstructs the light path, with a Pacemaker Speed Graphic this is worse as it's deeper into the body to allow for the shutter. Also I'm using parts left over from my main restoration as I bought the Super Graphic cheap just over a year ago knowing it had problems, so while I have the rotating back spare the actual focus screen holder etc is now on the restored camera

The Pacemaker and Super Graphic lens boards are the same (except for 4 raised bumps) but the Pacemake frame is about 1/4 maybe 3/8 narrower.

With either option I need to make parts, getting Super Graphic spares is hard so I'd need to make two sliders to use the lens panel, drilling it to attach the bellows would be fairly easy make the fit light tight a bit harder. If I could make some sliders then this would be the simplest.

Needs some thought