With the eccentric finished and installed, the half beam is getting very close - just the slide valve and nut to make and then the 'proper' assembly. Then it will be back on to the badly neglected double diagonal.
Zee - the rocking column was fabricated from mild steel strips - the horizontal members and the top and bottom bushes were silver soldered in, then the diagonals soft soldered in place - they are notched in the centre to allow 'em to fit together. Then the middle bit of the top bush was cut away to allow the beam to fit in. I've done quite a few minor changes along the way as I was not completely happy with the author's way of doing things.
Today I made the slide valve and took a good few pics as I went along, so if anyone is interested ....