Circa 1934 – 1982. Started in 1934 by Richartz Brothers of Solingen Germany. Was sold to Imperial knife Company in 1977. Imperial operated until 1982, then it was sold to Western Knives. The company specialized in shell handle knives.
I know in the 1980s and early 1990s we sold a lot of pipe smokers knives made by Richards of Sheffield. This may have been old stock that had been sitting in inventory for years but that was a common pipe smokers tool of that era. They did have a shell handle on them also, a nice blunt tipped blade for scraping the bowl pipe and a pick blade that was simply a long round piece of steel used for loosening tobacco when it was packed to tight or used to dislodge a piece of tobacco that might become caught in the shank of the pipe.
I believe that Richartz Brothers specialized in shell handle knives in Germany also.