Does anyone have some Phenix/Spacelas PT-40k galvos around that they could take a pair of calipers to? (Mine are still being shipped.) I asked them for a dimensioned drawing, and they sent me this:
http://kremvax.su/j4cbo/pt-40k-diagram.pdf
... which is a bit underdefined. If I had the overall dimensions of the galvo block, the beam entrance and exit heights, and the height of the highest point of the thing above the mounting surface, I think I could figure everything else out.