Yes they were
All four aircraft were from Skyways and three at least flew in a hybrid livery
Sometimes said to be operated by BOAC Skyways
My guess is it was a way around the stringent conditions in those days stopping any independents operating in their own right
Domestic airlines could only operate charters with BEA's approval and schedules in association with BEA.
This was probably similar with one aircraft in full BOAC as a token, I've not seen any mention of more than one and have seen various mentions over the years that BOAC only had one DC 4 which supports that.
As per original post there should be a case for a DC4 in BOAC livery
This was in the late 1940's so with all that was going on rebuilding the country and things changing rapidly it is nor surprising that this has slipped by relatively unnoticed. It would have been of no more than passing interest to a very few at the time.
It's certainly not well recorded.