The Autair 748s were used a lot on IT services far and wide in 1967- on Saturdays one went Corfu IIRC. Not sure I would want to go that far in a 748.
By 1968 I don't remember them being around at all with Heralds (and still the occasional Ambassador (only 'ZZ by then)) on the scheduled services. I think they spent a lot of time thereafter leased out including to LIAT.