I'm buying these clamps from Doug. Doug says they need a full 1" thick material to go between the steel bits. I was thinking to laminate some spare 1/2" ply for this purpose. I would have had to make several lengths of these laminations to have different length clamps for the heads though.
Then I got to thinking that I could make a bunch of foot long strips of the plywood, cut one in half and then glue them up so that they are each 6" offset except for two using the 6" pieces glued flush to a 12" piece. Then I could go to TSC and buy a big handful of bolts and nuts of the same diameter as the clamp pins and have an adjustable clamping system. Easier to store and I could easily make them any length I needed without too much extra overhang. Maybe I should use 18" long pieces with 9" offset - make it easier to squeeze in two bolts per mated pair. If I need just a little more capacity but not so much as an extra middle piece would give I could have some of the pieces not line up flush with each other when bolted together.
What do you people here think of this idea?