Photo 1 shows the front side of the jig, with two toggle clamps in place. In practice, one of them would always be swung back out of the way. ( I got the toggle clamp idea from Carsten.) The jig solves two problems for me. It raises the forms to a better height for me, and provides clamps positioned at the end or center of any strip.

The Plane in Photo 1 is a UK Stanley #3  retrofitted with a hock blade and rosewood handles.

Photo 2 shows the backside of the setup. There are several possible positions for the clamps to be fixed. Basically, I just drilled holes and backed them up with Tee Nuts wherever I thought I might need them.  Dimensions of the jig are 5 feet long,  3"  high, and 5 1/2" wide.