I think what can be inferred is that the Blu ray won’t go poster colors the tape will so i would trust the tape more than the bluray…
It is probably tinted and deliberately so like the tape. But not as drastically blue on blue like the bluray.
The poster is probably closer to real colors the day it was shot. Thus the tape is simply tinted the bluray is irrecoverable as it has tinted a tint.
Check the pic where i said “I had a go” looks like the VHS sort of so that was taking it to neutral.
Thanks for the info on the languages…
Thinking about it the best possible approach would be to use the old 4:3 R1 America - Universal Pictures (1.33:1) DVD and mix it with the VHS and try to make a dvd version… Will blend much better.
another possible color grade here too…
here is the dvd list