Had same problem with old 12/15 model. Solved it this way. In the groove into which the lever rests when the action is closed, I drilled a 1/4 inch diameter hole, 1/2 inch deep. Then, placed a rare earth magnet with a drop of glue into the hole. The magnet was installed so that it fits flush with the wood groove. Works like a charm. Magnet holds lever in position with no trouble. Go on Google to find rare earth magnets. They are very strong and come in various sizes.