CRs:
Regarding the Nuovo Record vs. Grand Sport seatpost differences, I'll limit my comments to the late era stuff.
I pulled out my Campy catalogs #17 and #18 and had a look. The GS seat post is not shown in #17, but in catalog #18 (page 54), a photograph is shown of all three posts is shown: the 1-bolt Nuovo Super Record, #4051/1; the 2-bolt Record (commonly known as Nuovo Record) #1044; and the 2-bolt Gran Sport #3800.
I'm hesitant to extrapolate too information much from one photograph, but here's what I see:
The most obvious difference between NR and GS seatposts is the clearance between the bottom of the horizontal head and the top of the polished shaft. The photograph shows that a NR seatpost has more clearance than the GS seatpost.
The late-model NR?GS posts on my bikes appear to be the same as the GS post shown in the #18 catalog. When measured at the back edge (where the "27.2" is marked), the short clearance on a GS seatpost seems to be about 6mm, while I'd estimate the longer clearance on a NR seatpost to be 8 to 10mm.
A second, subtle difference that is that the top (head) of the NR post might have some additional machining, and possibly a bit more polishing. I recall from years past that the GS seatpost had sharper edges on the head (where the horizontal and vertical surfaces meet). The NR edges were more rounded.
The brackets and bolts have changed over the years; #18 NR post seems to have the thinner steel top clamps and the alloy bottom cradles. The GS post has the thicker, less polished steel stuff.
Lastly, I'd agree with Dave Anderson's remarks regarding 'no discernable difference'. All of my late-production "NR" seatposts have the 6mm clearance. I also have one NR post in the beige box with all-steel brackets. It also has the tighter 6mm clearance between the shaft and the head.
At this point, I don't know whether my NR posts are actually GS, or whether the GS design superceded the preceding NR version.
Flame-less clarifications are welcomed, while venom, vitrol and bile belong in the toxic waste can.
Andrew Gillis (Long Beach, CA)