Personally, I've added clips or moved clips around on a good number of knives, and I wouldn't touch that one. You can't disassemble it, so you're going to have to be drilling through the bolster into a "closed system." That means right away you have to use the rear bolster, because a hardened steel blade is below the front one. Then you'll have the flash at the edge of the hole sticking through into the knife and darn hard to get at with a file, plus tapping the holes will be a nightmare. I managed to put another clip spot on a Spydie Police once, which is a similar problem, but it wasn't fun.
These are good, traditional pocket knives; if you'd like a clip, I'd suggest trading it for something a bit more modern.
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-Corduroy
(Why else would a bear want a pocket?)