Just want to say that this is an excellent piece of research on the CBS vs. Tokai topic!
Here's a little and (unfortunately) irrelevant tangent on the initial Norlin vs. Elger "lawsuit": I'm occasionally researching obscure Japanese import guitars I remember from my own past (or have owned), one of them is "Pearl" - yes the drum company Pearl. Long story short, Jack Westheimer helped Pearl in the very early 70s to set up a stringed instruments line and Pearl sold copies of Gibson, Fender and Rickenbacker designs throughout (to my current knowledge more in intervals) the 70s until 1982.
The funny plot twist: The Norlin Corporation was the distributor of Pearl in the US and their UK subsidiary, Norlin Music in the UK (maybe more places). The guitars were likely not officially sold in the US but they were in the UK, by Norlin. In other words, Norlin distributed copies of their own (OK) but also competitor (oops) designs at the very same time they threatened Elger/Hoshino USA with legal actions for doing so. 🙃
