Just to clarify... Richard referred to the SL as the first post-NR seatpost, but based on what Mark states it was the first post-record model with NR still five or so years in the future.
As for the SR one-bolt post, I have no idea when the finished-top to matte-top change took place, but I do remember the first time I saw the full-mirror model. It was in the fall of 1985. I had spotted a couple earlier in magazines on pro's bikes and was pretty impressed when my friend got one from Mel Pinto. In recent months, I've scoured over all my mags from 1982 to 1989 to try to piece together a few details of late-SR early-CR evolution. I'm pretty convinced that the dull to full-polish transition took place in 1984 to 1985. Of course this is not definative, but it is my conclusion using the "what did the pro's ride" approach to product intro dates. My general approach (for my one bike collection) has been to use what appears to be the latest-and-greatest-available based upon race photos and, to a lesser extent, ads. This can only tell me that something was available by a certain date. It does not indicate with any certainty that something newer wasn't also available. However, with time moving only in one direction and all... it is my feeling that an accurrate race bike restoration can include equipment from somewhat before the target date, but absolutely can not include anything that was only available later.
BTW - it is my understanding that Campy continued to churn out SR into 1987. Do you have any evidence that '85 is a better date? (Either way, I would set up a bike form '86 or later with C-record, but now I know I'm getting beyond the scope of this group.)