Hi there - thanks for the interest. The scope actually works really well. I think the longer focal length helps as the tolerances are not as tight as they would be with an f5 mirror. I ran out of time with the secondary, so essentially the mirror is mounted on a wooden block, which is attached to an aluminium strip which allows for collimation. However, once adjusted, it will hold it's position within the session quite well. The balance is also pretty good, although the 'tube' will slip in the mount if the altitude is low.
I think, as a proof of concept, it was a success. With more woodworking skills it could be made to look more sophisticated, but I quite like the aesthetic.
I'll take some pictures of the scope broken down, so you can see what I was aiming at with the portability.