I know of at least one NIB that went for 900 about two years ago...and it was a genuine pristine perfect NIB unfired gun with a perfect box and zero marks/blemish on wood or metal. These are not often found in any condition other than well used, and a true unblemished NIB is very difficult to find. "Very good to excellent" covers a very broad range of values within an even broader range of individual interpretations. The gun pictured by CFPython, from what can be seen, has some good honest wear and I would also guesstimate it in the $400-450 range...give or take a few bucks.
I just ran the price up a bit (overpaid). I just paid a little under $800 for a 99% (no turn line) Official Police in the original box with accoutrements. It should be in tomorrow, and I will post some pix. I have some shooters and wanted a collection piece. I guess I wanted it a little too badly. I just haven't seen many in perfect condition, and wanted to jump on this one. It was one other guy and me, and I guess I wanted it just a few bucks more than he did.
Never hesitate/ Bought one as nib with papers around 12 yrs ago for $219 from Simpson Ltd. The one time I did hesitate was a few yrs before that , I felt a 5 inch 95% Detroit PD one was overpriced, oops.
They were introduced in '69 and not sure what the last year for them was. I'd say '69 to about '71/72?? I believe what you say about the action. Mine is butter smooth and smoother than my Trooper/Lawman MKIII's.
Made from 69-72 ,with some trickling out after that. Great revolvers ,victims of stubborn Colt fans to accept the new action. Colt should have used lighter springs, offered a 2 and 3 inch round butt version ,as well as stainless ,and a 22 version. But they didn't. Too bad ,but your gain. I have 2 and really like them. With semiautos being hi cap limited in many places ,new shooters, especially women , buying home defense guns , the revolver is making a comeback. A revolver like the OP Mark 3 , bull strong ,and loaded with 158 lhp, is about the the perfect choice. The Mark 3 Official Police is about the same weight as a S&W K frame , but much stronger.