Mine came from Honda, but all HRC jet kits are now listed as "no longer available".
When I sold my '28 racebike I sold a couple of '28 jet kits on ebay, they fetched over £200 each.

The jets are generic and available from loads of places, the rest of it would appear to have been NSR specific, they turn up on Yahoo Japan all the time but are fetching more money every time.
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