There are some interesting aspects of the Chinook story and of their connection to Coopers as they were winding up their show. The Chinook SR cars were as I understand it pure copies of McLaren 1B or McLaren-Elva Mk2s, but fitted with Chaparral 2A clone bodies. Years after that time, I was buying other racecar bits from a shop in Toronto's east end and the proprietor introduced himself as "that Indian kid working on fiberglass in the back room at Fejers--the kid nobody noticed." Barry was the first name--I can check my notes for a last--and he was working on Porsche 944s from the Rothmans series--he knew his stuff. The important point here is that he told me the plug for the Chinook bodies was scaled up from the 1/24 slot car common in the day--Cox I think. They were the first,but soon other brands were producing--I have 3 slightly different variations myself. The body shape captures the form fairly well to my eye--the later Mk4 with the shoulder rads doesn't work so well to me.
Coopers as I was told sold virtually everything of value to Fejers--wheels, uprights and drawings among them. They were then sold to a raceshop near Barrie Ontario--I may find a name.
I heard a story at Shannonville one year when Fejers' Indy car had been dragged out of storage and put on very sorry display, that Bruce McLaren had looked at it and eyeballed the suspension geometry as "way out of date"--can't speak to the authenticity of that comment myself--very much secondhand.
HOWEVER--to put the Fejer brothers down in the "copy cat" category would do them great injustice--much of their engineering--particularly their Indy engines--was innovative and well thought-out.
Hope this has been helpful.