You're welcome!
Actually Pentax (like a lot of optics companies, including today) didn't actually manufacture stuff. Instead they contracted with manufacturers. I would bet the DCF WPs were made by Light Optical, one of the finest optics factories in the world. They've been making optics for various companies since the 1950s--in recent years including some "alpha" companies.
Another example would be the Pentax rifle scopes that appeared around 20 years ago. They were actually made by the Colorado Burris factory--and in fact except for slight variations in bell-shape shape were obviously Burris Fullfield IIs, including the Ballisitic-Plex reticle--which Pentax called something else. This was admitted to me by one of their marketing guys, after I measured the length of a 3-9x40 Pentax and a 3-9x40 FFII made then--and compared the reticles on a target at 100 yards.
