Well, I was there. I was racing in the SCCA at the time and both Bob and Pete were racing way before the introduction of the S30. Here's what Peter Brock was doing https://bre2.net/the-racing/hino/Bob Sharp was racing his Fairlady 1600 and 2000 roadsters throughout the late 60s. The Datsun USA competition department was established (bare with me, I have to look up the year. I have copies of the original Bulletins) so Nissan was not " setting up a new race program in a foreign market ". Further, the SCCA didn't have a class recognition for the PS30 or the PS30SB because it wasn't imported and sold in the USA.
And the crankshaft vibration problem; do you wonder how little is heard of Bob Sharp's problems with the crankshaft? What does Bob's engine builder have to say? I might suggest that you take Peter Brock's presentation with a grain of salt. If you know Pete... My point wants to be that the "armchair" guys have spent a lot of time, invested a lot of money (a big, fat lot), spent years discussing issues (how long have we been corresponding, Alan a decade?), and compiling libraries to have a pretty good understanding of what seems to be what. Laddie, when I started in this forum thing, we were discussing Milbrecht Goertz! In all probability, this forum is the definitive book on the S30. There have been all sorts of topics discussed ad-nauseum within this library.
Oh! If you want answers from Bob Sharp or Peter Brock, why don't YOU ask them? Tell us what you hear.
Thanks for the pictures, Blue, Mr. Hoover.