Sitigeltfel, nope they did not have cl44s as far as I know- but they were certainly manston-centric and mostly used Vanguards. You might have been thinking of tradewinds or ias or even tmac. or Young cargo from belgium (aka the flight number hijackers)
I dug out my logbooks and found on 9dec 78 (not 74 as I thought) we had a cattle charter manston - Casablanca using Britannia G-AOVF with the above mentioned bull mayhem.
We returned via almeria and thereby hangs a tale. We loaded 18 tonnes of cucumber but on taxi there was a"thud" and we lost all hydraulics. Back on the ramp the FE got out 10 cans of coke and said "drink this I need the cans" whereupon he brazed a pipe from aforesaid cans to make an emergency repair to get us back to Manston. We were tempted to ask for the arrestor barrier on arrival but the captain stalled the Britannia onto the numbers and we rollout without touching the brakes- a superb performance.
And 18 tons of cucumber has a most intense smell