Not too many made with the sunroof. Only 6,822 came with it. Here is the article:

1972
Unquestionably, the third generation Nova had secured a spot in the hearts of street savvy runners, particularly those with a penchant for going fast without looking the part. As a consequence, it also secured a spot on the Chevrolet hit parade as its popularity was reflected in sales figures. The restyled Nova, which made its debut in 1968, was a handsome package, to be sure. The boxy lines of its predecessors were exchanged for a more fluid, muscular design, and the "new" Nova was and instant hit. Especially when it was fitted with big-block motivation.

But the factory-installed big-block Nova had its last gasp in 1970. Despite it small-block power, the popularity of the Nova Super Sport continued into 1972, without major revisions - stylistically or under the hood. In fact, the demand for Nova Super Sports gained momentum as a total of 12,309 were built in 1972 compared to 7,015 in 1971.

The '72 Nova SS could be had with only one engine, although buyers could specify either a three-speed automatic or a four-speed manual transmission to back it up. The engine was the L48 small-block, displacing 350 cubic inches and fed through a single four-barrel carburetor. Its horsepower rating was pegged at 200 (net horsepower figures were now used). This was good enough for 15.4 quarter mile ET's with a trap speed of over 88 mph. A unique option was added to the Nova line midway through the production year - a sliding fabric sunroof known as the Skyroof. Officially called the Ventura II Folding Sunroof, it was installed on 6,822 Novas in 1972. Each color carried it's own RPO code: White (RPO-WV1), Black (RPO-WV2), Blue (RPO-WV4), Pewter (RPO-WV5), Covert (RPO-WV7), Tan (RPO-WV9) and Green (RPO-YH8). The Rally Nova continued production in 1972 with a total of 33,319 built.

The article can be found at
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It took some looking to find this info. Found some good reading though.

Kevin