Robert:
I don't know enough about the curtain call made by 71 in the '80's to comment with certainty.
What I seem to recall is that some individuals took it upon themselves to steam the engine and run it back and forth on and immediately behind the site the train had been on display above Central City for many years. This was sometime in the mid-80's, as I recall, and the trackage was the same as used by Linsey Ashby's operation before he moved to Silver Plume. Then, after having sat untended for a couple of years or so, a parking lot was built on the site of the display and the surrounding area and the train had to be moved. There was an attempt to spirit the train out of town by some folks to Silver Plume, where it could more appropriately be displayed, and maybe returned to service, but the effort was blocked by a massive public outcry.
71 was moved to Blackhawk, where it was going to be "restored", but time and lack of money caught up with the project, and a Casino was built on that location, as well. The engine ended up being repainted and put on display again in the middle of a street with Combine #20. Because there was no room for the gon, it was moved to a park.
Phil Johnson, John Hammond, or Rick Steele can add a lot more detail to this, but I believe my version is essentially correct.
As to my comment about the 71's cinder catcher being crooked before being taken out of service, I mean to say it was that way in the thirties. The engine was steamed a few times in the '80's, but not really "returned to service", in the sense of having been reshopped. I never got to see the 71 under steam, and I really regret that.
Mike