I used to race a pre-proarm NSR ('94 vintage). It was supplied by AP Honda with their 'trick bits' fitted. I threw it straight on the dyno and it made a whopping 21hp (Dynojet).
Lots of dyno runs later and it was making 39hp (Dynojet) and almost capable of 120mph (193kmh).......almost. That was real mph. If we'd kept the OEM speedo on there it would've shown considerably more no doubt. I was an 9 stone race snake at that time.
As for testing all the 'sport' 150's. This was done at the Castrol (Thailand) Technology centre in Bangkok, using a rolling road. Only the Kawasaki KR hit 160+kmh. The NSR and TZR followed up with 155ish, with the Suzuki RG trailing the field at around 150. This was an industry standard dyno/rolling road, not a Dynojet (pub standard).
When we tested a stock NSR150SP on the Dynojet it too made a measley 21hp as stock. Fitting a pipe added chunks of power.
Also, when I was at Harc-Pro we had the task of preparing the HRC NSR150SP's. This involved us spending a week in a cold and secluded warehouse rebuilding 20 NSR's to HRC spec. No engine mods, just bolt ons. They allegedly made about 30hp in this 'SP race' spec.
Anyway, I'm not the authority on NSR150SP's, but after spending three days sitting in the dyno room while the R&D staff from Honda tested the preproduction model at our workshop I'm guessing that I do know as least as much as the next bloke.