I just picked up one of these, but I'm not likely to see it for four or five weeks-

There's nothing specific about it that I can find- a few references to people picking them up, but no results-
It's likened to a G-Claron, or Componon, or Hexanon, depending on where you look.

Has anyone got any reports, particularly on coverage? Image circle and circle of illumination, vignetting characteristics?

I've also noticed someone once mentioned a Wide Field JML 300, but there's no other reference. Might this be the same thing?