Hello "IomMan", and welcome to NSR-WORLD.
I love the Cabin colours; for some reason it's a very rare to see one.
We use and recommend Rock-Oil Synthesis 2 Injector, but any synthetic 2T oil today is infinitely better than the Honda GR2 specified 30 years ago!
Many here swear by Motul 710 or Castol Power1 (formerly TTS).
Restriction doesn't strictly limit RPM, but stops the RC Valve opening fully in the higher gears, so you'll probably feel the motor running out of puff as speed increases beyond 70mph/112kmh. The NSR is geared low however, so even when delimited, unless you change the final drive (dropping down to 40T on the back for MC21 works well) it makes little difference on the road usually.
MC21 derestriction is incredibly simple though, needing nothing more than some side cutters, a soldering iron, and a 20mm hole cutter. (And most likely a re-jet.)
A shame you didn't check/post in classifieds for pipes... I have a brand new set of TYGA's here in the UK ready to go!
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Andy.
NSR-WORLD.COM
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