I like Italian parts, especially old Campy ones. I also find it really interesting that at one point Campagnolo, the top manufacturer of high end racing equipment in the 80's, thought it would be lucrative to market their parts to Keirin racers in Japan, which was a pretty niche market compared to European road racing. I guess at some point they tried and their gruppo was rejected, partially because of a pro-japanese bias and partially because of incorrect design, so they changed some things and were accepted in 1987*.
Heres the 1991 Campagnolo Record Pista Gruppo with a smaller image of the Keirin group. Theres a couple noticeable differences. NJS hubs can only be high flange and 36 hole, so 36h Sheriff Stars were the natural choice. The other main difference is the seatpost, Campagnolo swapped the 1-bolt bladed post for an NJS style 2-bolt.
Another subtle difference would be in the threading. Campy NJS bottom brackets are English threaded, as the NJS only approved English threaded bottom brackets.
The headset is English threaded as well, but with the weird NJS 27.0mm crown race diameter. These NJS Campy headsets look more like the super record ones than the later chunky C-record ones, probably due to ball bearing diameter restrictions?
I also find it fascinating that Cinelli made stems and bars that were approved by NJS, given that the old Cinelli handlebars have been known to de-sleeve. The NJS Cinelli stem looks like a 2A track stem and the bars look just like regular 67-59 Pista bars. Maybe there was some design change to please the NJS.
But finally, the holy grail of Italian NJS rarity has surfaced. I was browsing velospace when I spotted this NJS stamped Cinelli Unicanitor saddle.
This has got the be one of the rarest track bike parts available, an ass raging unpadded Unicanitor saddle with Keirin-width rails. Don't know why you would ever want to ride this, but its collectors value is certainly through the roof.
Note: I took a few photos from this flickr set, which is worth a look if you want to see more photos of NJS stamped Campagnolo track parts.