I have got the Plaubel Rada 6x9 120 roll film adaptor working again, it was rusted quite badly, but it has cleaned up, sprayed with rustproofing undercoat, and satin black finish. The inside was OK, no damage at all.
I fits the slides of the Agfa, but needs a careful check that the focal plane is the same as the ground glass and cut film holders, usually 2mm back from the slides on 6x9 cameras. once checked the same as the glass, the Agfa focus scale and helical focusing can reliably be used, rather than having to use the glass screen, or just infinity.
It then makes the plate camera as useful as the Agfa roll film version, but with more options, such as much easier colour photography with normal 120 roll film.
Looks like a very useful camera with an excellent lens fitted.