I suspect that these are indeed OX chassis, namely the OXA, Census Numbers L 4410861 to 4411060? I have a photo somewhere of an OXA Anti-tank truck, as posted on the previous forum
It would appear that they were never actually used in the A/T role and instead were used as armoured recce vehicles?
Has anyone got Mr Vanderveen's book with the armoured Bedford references in it please?