Designed by Barry Minot in the late seventies, these were interesting, if somewhat small even for 25mm, ranges. As a source of dungeon artifacts, they were great!

It appears that at least the Thane Tostig Range line was sold to Eisenwerk Industries somewhere between 1978 and 1980.  I don't know how long Eisenwerk was around, but most if not all of their miniatures were later produced by PewterCraft.