Rick, you need to very gently stone or sand a small amount of material off the heel of the tang where it sits in the closed position, see the picture below. Don't even think about using any kind of power tool, grinder belt sander or even a Dremel, the lightest touch on one of them will be far too much and the opener will sit up about 10 degrees. (ask me how I know

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I use a fine sharpening stone and then polish on my buffing wheel.
Try a couple of passes along the stone and then trial fit. You can always take a bit more off, but it's damn hard to put it back and if you then have to stone the "toe" of the tang you will end up with weak snap.
IMPORTANT: The red ink on the tool is only to show where to remove material from. NOT how much to remove.