Hi. Do you have one of the master cards RCA sent with the testers? If you do the cards can actually be made out of heavy card stock about the same thickness of the regular cards. Just cut around the outline and make the bottom edge is straight, the notch in the right place, and the holes where they master card shows them. RCA published punching data in a couple of manuals that covered quite large number of cards so it should not be too difficult to make some. Being cardboard, the RCA cards actually punch easier than the Hickoks and they do not seem to need as many holes punched. Dave