I think Howell is a little off on his dating of the "flow box" for head work to the 80s. I was running a flow box in the 60s.
Also, we used high speed photography to record valve train motion. Had a mechanic that made plastic cockpit covers during the war, and he made things like plastic rocker covers for us.

I can't recall Bill Howell, but I did do some projects with Vince Piggins.