Hmmm... the Kydex sheath that came with my Dozier knife...
http://www.dozierknives.com/index.ph...=article&id=78
...has cracked twice. (It's the horizontal orientation sheath, which tends to catch on things in tight quarters. I'm also going to have him make me a more secure & deep vertical sheath for carry in the rough bush country. Walking through the willows in bush Alaska is kinda like having a dozen Rome pickpockets "working" your belt!)
I sent it back the first time and, as I recall, it cost me ≈ $20 plus shipping to & from, to have him replace just the cracked part. You mention that Plastic Welder though; will it actually soften and then "weld" this material enough to consider the crack solidly repaired?
(Of course, your blade should always have a lanyard fitted when you're out in the bush...)
BTW, I've dedicated a tiny part of my day-to-day life to wearing this blade out, and so far, I can't. I do not baby this knife, and I use it for pretty much any actual cutting/knifing duties, opening packaging materials, trimming small branches around the garden (no hacking,
NO PRYING, no abuse.), and as a non-firearm self-defense "device" when walking the mean streets? Excellent choice, and very reasonably priced! One day Doziers will be classified like Randall collector's blades, I guarantee it!
That D2 tool steel Bob Dozier uses? Fantastic knife stuff, let me tell you!
As a cutting edge artist, dang, Bob! YouDahMan!