These two bar clamps look home built. The top one has a slide mechanism built in for the push jaw. I’ve never seen that before. The turning crank also looks home produced, especially as it consists of a threaded rod and a large nail.
The bottom one definitely looks light duty. The screw jaw looks a bit flimsy and the turning knob might not bring enough torque to bear for strong pressure. Still, an interesting specimen.
-- Ni faru ion el ligno!