I'm sorry, the name of the knife is C
Ampanion, not Companion. I made a mistake. I used the Wayback Machine web archive to get a look at Camillus' old website from before they closed. You model is not listed as a standard offering in their Becker like (here's the entry for the BK2 Campanion
CAMILLUS CUTLERY CO. - Quality knives since 1876)
I've been checking with some collectors that are more knowledgeable about Camillus than me and they told me that the BK2 Campanions with partially serrated edges were made by Camillus to be sold to the US Army. The model was called BK2SG and it the NSN # was 1095-01-493-1798 (some websites list this number as the one for the Becker BK11 "Brute", but I've seen it printed on an actual BK2SG box in person)
So yes, you've got a rare model that might be of interest to Camillus colectors or US military knife collectors. Still, an NSN number does not mean it was issued. There are lot's of knives with NSN numbers. Do you have the box and paperwork? I've seen these sold for around $160-$230 depending on condition. Yours seems to be in pristine condition, if you've got the box, Camillus business card and CLP cloth it came with, you'll be able to sell it for a good price.
This were massed produced knives, and while they are rare they don't fetch very high prices. A new one from Ka-Bar is around $65 (from
Shop for case knives, Kershaw and other discount knives at Knifeworks.com), so more than $200 should be considered a good price for a "rare" Camillus. A hardcore Camillus fan might pay more.
Just to clarify, Becker didn't go under. Camillus did in 2006. The Becker knives are still alive and well and made by Ka-Bar now.
It's a nice variation on a very good knife, unless you need the money, keep it and use it.