KLM/Martinair have not returned. Don’t believe they have had scheduled service since pre covid.
Air Belgium have been operating three times a week using B748’s and A332’s.
ASL and West Atlantic operate on contracts with Royal Mail, DHL and FedEx. Both have occasional charter flights but nothing scheduled themselves.
CMA CGN operates for Turkish Airlines and flying under Turkish flight numbers.
Also to note Ethiopian Cargo does go into LHR plus a number of the other airlines you’ve mentioned will use belly freight space on their own passengers operations.