Originally posted by hangu Ralph Ines sounds like the man for you in this case, his rates for manual primes are extremely reasonable, I would even go so far as say cheap.
The cost of this lens is only ~$50-60 on Ebay, well below what the repair/shipping cost would be for broken apertures.
Many thanks!! Ralph Ines sounds extremely reasonable. As for buying another 24/2 PK lens -- I just now searched eBay for VIVITAR 24MM PENTAX and the only hit is for an M42 f/2.8 in the UK for about US$212!!! Of recent sales, there's almost nothing comparable or better. Ralph Ines' quote of US$48 max (w/ return shipping) looks like a real deal.
FOLLOW-UP: So Ralph said the fix would be easy, but advised me to check the rear element for fogging, indicative of glass separation. Dang, there it is. The optics are soft. It's not worth fixing without a rear element replacement, and good rear elements haven't shown up for a long time. Dang. Guess I'll eat worms and die.