I won those grips on the 4' Mod. 28 on an e-bay auction some time back. I got them from Keith Kincade from Fresno, California. I believe he makes them himself and auctions them. I haven't checked e-bay for a while since I won't use Paypal so I'm not sure he's still doing this.
Mine is a late 1964-early 1965 model. It was missing the original service stocks, and wore Goncalo Alves target stocks when I got it. I put on these after market stocks for the picture. It usually wears Pachmayr Presentations or Hogue's for range work.
All I can say is that my wife hates you all because you just added another gun to the list. I hope you are all pleased with yourselves. Of course if any of you can't live with the guilt of disrupting a happy marriage please feel free to send me one of those beautiful guns.