Originally posted by lytrytyr I suppose they made up a batch, and found enough takers in the Japanese market for it to be worthwhile.
They also offered the FA 20-35, and an FA J zoom.
The Japanese website was quite amazing up to a year or so ago,
with medium-format film cameras (645N, 67) being offered for the "professional" market.
I don't know if you can still find the site on the wayback machine,
or if someone archived it.
I think that part of that explanation (the FA and FAJ's) were a stock pile caused by overproduction around 2000-2005 when Pentax didn't grasp how fast film SLRs dissapeared, and since they had it in stock, it was for sale. Part of it is probably just that they didn't updated the page until Ricoh took over (Hoya probably fired the guy who was supposed to do that...).
The 67 and 645 lenses were probably there because the medium formal film camera market died more slowly than the 135mm film SLR market, especially in Japan, and Pentax 67 and 645 cameras was manudactured a few years after the millenium turn.
But it appears that the SMC Pentax-A 50mm f1.2 was produced for a while a few years ago. It seams to be the only reasonable explanation to why those lenses appeared labeled "assembled in vietnam". Perhaps it was the graduation project of every new technician on the lens assembly lines in their vietnam plant?