After drilling the perspex base, even with a drill press, I was off in my alignment…grrr. This was a combination of using a broken 1/32″ drill bit, inaccuracy of the Dremel drill press base and that I didn’t centerpunch the marked drill holes accurately enough, nor checked the prospective drill hole position sufficiently. Other photos indicate that this level of inaccuracy didn’t turn out to be a problem in practice. The edges of the perspex in this photo are pretty rough, due to cutting the perspex with a hacksaw by hand (no bandsaw available). After this photo, I flattened and straightened the edges with a hand file. Some of the edge connector pins and 1″ 2-56 bolt for reference. I ended up using a 1/2″ bolt as a centre pin.