Hmmm, you have just given me an idea Alistair. I need to move my primary up about 20-30 mm to get my DSLR into the focal plane. I might replace my flat alum supports with box section as you are using in your cell. Be a heck of a lot easier than cutting the truss tubes or making recessed spacer blocks as I was planning. And reversible. Excellent !!
Many thanks
