Afew thoughts on the Nimravus.
(1) For 'covert' carry, couldn't the handle scales be easily removed to lower the profile of the blade? I know that you lose a lot of the ergonomics that way, but I would think you reduce the profile a lot.
(2) With the Cub, the OAL is only slightly longer than the REKAT UNK, which I have carried in the front pocket of my jeans quite a few times, using the kydex sheath as simply a slip sheath to protect me form the edge. The Cub is about a quarter inch longer, which would still fit nicely. If the sheath (newer one) that is supplied with the Cub now can have the attachments stripped off to make it just a slip sheath, that should be an easy carry.
(3) Regarding neck or inverted carry: kydex is very easy to drill. Put some holes in the tip end. I've heard that the retention is not great enough to trust inverted carry. Well, I can propose a couple of mods, but not sure how they'd work without looking at the sheath. First, you could try heating and reforming the sheath. I wouldn't try this, but I've heard it's easy. Someone else could talk about that. But, what I did with my REKAT UNK was really easy, and didn't require heating the sheath. I drilled a hole near the entrance area of the sheath. I put a zip-tie through this hole, and pulled it down tight. It has just enough flex to allow the UNK to be withdrawn easily, but increased the amount of retention of the sheath.
Someone brought up the fact that for the amount of money you will put into a Nimravus you could get something like a Rinaldi. Well, true, if you get the M2 Nimravus. But, if you go with something like the Cub in M2, and shop around a bit, you can significantly reduce your cost by comparison, and still have a steel that is every bit as good, except in corrosion resistance. So, it depends on what you want to do with it. I look at the Cub, and then look at a Rinaldi, and think "Oooooh, that Spook looks Sooooo nice. But, then I look at the steel and the price, and think, "Ooh, that Cub might be a little more practical, for my needs."
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Work hard, play hard, live long.
Outlaw_Dogboy