Here's a couple photos of the latch on the wooden lid on the rifle I'm working on.
This is the underside of the one piece lid showing the long spring latch which engages the stationary catch as the lid is slid shut.
This photo shows the spring latch and the stationary catch removed so you can see their notches and how they work together. The release button atop the long spring is turned from deer antler and goes through the hole in the lid. Pressing it pushes the end of the long spring down to unhook it from the stationary latch. The long spring is made from a section of recoil starter spring. The hook on the spring is made from bar stock and is riveted to the end of the spring. The latch is made from ~.060" sheet metal.
It works great and I have used this type of latch on most of the guns I've built with sliding wooden lids ever since I lost a lid that had the usual spring catch hanging off the rear end of the lid. As the final shaping of things is done I always recess the release button a bit so it is unlikely it will be bumped accidentally resulting in a lost lid.
Thanks for your interest.
Ted