Strictly speaking you don't have Nuovo Record cranks; they are just Record. There never was a NR crank. Though we know what you mean when you say that, so there's no need for me to be so pedantic.

Record cranks originally came with Record BB, which is the style with thin cups and a wider stance between the cones on the spindle.

The NR BB, which is the only "Nuovo" part of a NR crankset, added the thick "rifled" cups and the corresponding spindle with cones closer together.

So it sounds like you have a Record spindle. Those are actually rare these days, except in track and triple — Campy never made track or triple spindles for thick cups, back in the Record-NR-SR era. If your crank is a double, you shouldn't have any trouble finding a double NR spindle, or something compatible like Gran Sport, Sugino Mighty, Gipiemme, Ofmega, Avocet et al.

If you have a Record (wide cones) track or triple spindle and want to keep it, then you need to find Record (thin) cups.

You also need to watch out for the change in spindle and crank that happened about 1978, where they made the chainrings sit further away from the back of the crank, and made the spindle longer to compensate. So the chain-line is the same but the crank and pedal are ~1.5 mm further outboard. There are various markings that sometimes tell you if the spindle is post-'78, but they weren't consistent, so it's best to measure and compare to the charts listing the lengths for pre- and post-'78. Sorry I don't have the chart handy but someone here will give you a link.
Another route, rather than measuring and researching, is just mount it and see. Sometimes there's even a reason to mix'n'match between pre- and post-'78 parts for a particular bike. Note this is unrelated to the Record versus NR issue. Both Record and NR came in both pre- and post-'78 dimensions

If you still have questions, help us help you — show some pictures and measurements. If you don't have calipers, this is your chance to get some! Starting around $10 for usable, not pro grade but way better than a tape measure. Every bike mechanic should have them, even amateur home-players. I still have the simple vernier calipers I bought in 1975, and I use them practically every day. I thought I couldn't read the vernier anymore due to aging eyesight, but then I hit on the technique of taking a picture on the phone. Pinch to zoom, et voilà! Now I can easily read to a thousandth of an inch, with no finicky dial, or electronics that run the battery down even when turned off, as so many cheap digital ones do. Maybe look on ebay for some nice used calipers versus getting Chinese garbage.