E., given your interest in Dagors and such you need to know that according to Eric Beltrando M. Kiritsis, Boyer's last owner, cemented Beryl cells by hand. Held the glasses between his fingers, didn't use V-blocks.
I was glueing a Rapid Rectilinear. I'm sure I could align the edges by feel, but I liked the idea of letting the balsam set with no chance of it being knocked out of alignment. You know, belt & braces.