Thanks everyone
Eric, you will hate me for saying, but out of the blue, Baader contacted me re their using some of my UHCS filtered images on their website last year. They then sent me their prototype 7Nm HA filter free of charge
It is unmounted but I can attach it to the MPCC for the 10 and 6 inch scopes, or sit it in the back of Berts 300mm lens.
Scott