Not quite Southampton but…
found these pics on the “Old Truck Accident Pics” thread (thanks to “neversweat1”), they are of a PM Combes truck based in Andover.
PM Combes were a timber merchant and also had a saw mill/machine shop in Toynbee Road Eastleigh from where they ran Ford D series artic and a Ford A series rigid (I know this as I did an apprentiship there in mid 70’s) They were then part of the Montague L Meyer Group which used to import timber and had a yard in the docks (I seem to remember it being close to Dock Gate 10) where several local Co’s. would haul timber and ready built crates (for Fords amongst others)
one Eastleigh based carrier was R Smith and Son who ran out of their farm in Stoneham Lane.
I think the main haulier had some motors in Meyer livery but who it was escapes me at present.
Colin