I think your description is right Malcolm. Three cameras, LRGB, hadn't thought of that one. I liked the possibility of see, guide & shoot through it. So another possible idea. I'll just have to load it onto a scope and see what happens.
Excellent

.. this is gonna keep me amused for a while.
And my new super PC has arrived. M92 with i7 processors, 32 gig Ram, 2 terabytes of HD and some super graphics card I can't remember the specs of. It's going to be a busy weekend.