Yip: study the pictures I posted of a Buck'sCo. box in the opened position. There is no set length for anything here. I usually made the catch spring first and set it into the end grain of the butt under the buttplate. When I make the catch and silver solder it to the patchbox lid, I do not cut the notch in it until the spring catch is installed. Then I black the peg with felt pen, close the lid and see where the catch on the spring has stopped. Then I cut a very fine nick in the peg and try it again. I repeat this process until the catch spring holds the lid shut, without any extra travel so there is no slop.