Haha, I see now I am not answering your original question at all.
Back to square one.
- Yes, I believe the = bank protection marks are displayed at 67 degrees.
- No, I cannot find any reference in FCOM (present version) with the exact wording to declare so.
- To settle your argument - as long as former versions of FCOM and (unchanged) DMC standard numbers are not allowed as evidence, you would need a test:
- fly the A/C to the bank angle limit and compare the position of the sky-pointer to the mark, or
- put an angular ruler / protractor on the PFD. [at least one engine running most likely required]
Splitting hairs, are we not?
FD.