[avandonk]

I have changed my mind and I am going to build a conventional gable roof design with the two gables running off to both sides. The walls will be 1.6-1.7m tall. The apex of the gable will have lots of ventilation. It will all be done in wood to minimise radiant heating of optics. I promise to bolt it down Roger.
I am currently testing and adjusting a focal reducer/field flattener setup for a Meade SN10 for a full frame camera. Would you believe f/3.4_3.6! and flat field with almost minimal vignetting. So far looks very promising.

Bert