Got a pic? I have no idea what HH-80-K refers to. The only model I refer to with these cryptic numbers is the HH-80R, which is Pilot’s knurled grip “ring” drafter (with rings in red, green, and yellow).
If we’re talking about the same pencil—the ¥500 drafting fauxbois that’s really the “younger brother” of the H-1005—then yes, it was also available in 0.3. Though I should note the non-black variants do not appear to have the same fauxbois finish.
You actually bring up other desired pencil(s): The non-black variants of the H-50-R (I’ve lost an auction for the red, and I’ve seen YOUR white…. Outside of those two colors, I’m not sure if or what others there may be, BUT(!!!), I’m also after any and all versions that I do not have.