Cyclone82,
The knife itself is a Barlow pattern. A bit different than your average barlow (addition of Toothpick & Tweezers as well as aluminum bolsters) but a Barlow none the less. HY Kaufmann & Sons of Solingen, Germany were started back in 1856 and made knives up until 1995. The K55K and Mercator where trademarks of theirs.
And that's about all I kind find on them. Not sure when your knife was made but as far as finding a new one you'll have to hunt around for a NOS piece. But if it is just the pattern you like there are tons of versions of the Barlow out there now made by numerous manufacturers all over the world. Matter of fact I don't think there is a slipjoint maker out there now that doesn't have a Barlow in their line up.
2xTap