A journey of a thousand miles begins with one step. Here's the first and second prototypes for the support arms. The top one (the first) was made from flattening 3mm aluminum tube and is quite strong. The second, "more scale" arm took considerably more effort. First, using a metal guide I cut in the groove with a dremel tool. Then I cut out the bar shape around it and filed off everything that didn't look like a support arm.
The M2 bolt heads may be too large, however. I could go down to 0-80 screws.