I'd be interested in a picture as well. It looks an interesting solution to the problems of versatility - I've not come across the "Unisub" coupler previously, but it sound interesting.
I have come across the use of a Regal to provide the pedal 16ft, and found it surprisingly effective - that was on http://www.npor.org.uk/cgi-bin/Rsearch.cgi?Fn=Rsearch&rec_index=E00937
- a van Vulpen house organ which I played a few years back. I'm considering free reeds for the pedals if I ever get my house organ build off the ground.
Have you sent details to NPOR? We are trying to be comprehensive in our listings (and unless the info is in the public domain elsewhere, or the owner requests it, we don't publish the full address of current house organs, just town and "Private Residence".