These are photos of the Indiaman service, operated by Garrow-Fisher starting in 1957. The Wikipedia article conflates details of this service with another one, the Albert, operated by Albert Travel, which started in 1968. I noticed the discrepancy because the photos are of a single-decker bus, not a double-decker.

See here for much better Wikipedia article that keeps the details straight: https://en.wikipedia.org/wiki/India%E2%80%93United_Kingdom_b...