As to whether they're still made, the answer is 'no' for the moment. They used to be made by Top of the Line, but that company went bust quite a while ago. Some years ago, Cutting Edge Kites got hold of the licence to make them and started building and selling NSRs again. The sails were sewn by the people who made the sails for TotL, but these 'replica' NSRs had more modern spars, fittings, connectors, etc.
Then earlier this year, Cutting Edge Kites also went out of business, which, for now at least, seems to signal the end of the NSR replicas. Personally, I was lucky to pick up one almost new replica NSR from someone here on the forum (hi Steve!), and a second one directly from Cutting Edge Kites, just before they closed down (mine was part of their last batch). Here's a picture of my set (not easy to fly and take a picture at the same time!):
Slow, precise and noisy. Great kites for pair/team-flying!