I am making some lens board adapters to use Technika boards on my Sinar. I would like to have a slider to clamp the smaller lensboard in place. I'm thinking of the bar with the ends bent up to make a handle and then two diagonal slots in it to slide forward and clamp the edge of the board. Is there a name for these things? Where could I buy one? When I started this project I was going to take these parts off my old Omega 45E camera but have since sold the camera intact. Thanks.