Forget what I said about 'reintroduced at the end of the 70's' I have 2 Thin Blade R-1 1971 before my eyes and I also received a lot of Thin Blade V-1 1974 this morning. If they phased them out, it was only for 2 years top.
I shaved with a 1971, last year, and completely forgot about it. Shave was good.