Thank you for that detailed response @David Mullen ASC. Glad that one of my favorite films 'Greystoke' played a part in this history too. As a first time potential 35mm film camera buyer I am going back n forth between 3 perf versus 4 perf (4 perf is more available at affordable rates - and setting aside the more expensive cameras that do both)) and they both have different benefits. 3 perf is attractive bec we now have great 1.5x anamorphics like the Atlas Mercuries and also one can do standard 16/9 or 17/9 without 'wasting' film. I love Spaghetti Westerns too, but shooting everything in techniscope may not be the best use of the investment! (Or maybe it is!). I know I can rent too of course, but I like the idea of owning a versatile, light, film camera like a moviecam SL Mk1 or MK2 for example, that one could shoot multiple formats with.
@Joerg Polzfusz appreciate the reference too, thanks.