Info needed: Trailer socket Humber one ton

[Robert Sexton]

The trailer and Humber will stay the desert sand colour. No real reason other than I have three other green trucks and this one will look different.
The Humber cab looks to have surface rust without any real penetration,I have dissembled the mud guards,doors and roof hatches as I thought that they were the most vulnerable. I put the lack of rust down to the very low humidity and being under cover for such a long time.
I fabricated a new winch hatch and that is now in place.
I am a new boy to much of the above so I am on a steep learning curve.
The brass ID plate on the trailer says; TRAILER,1 TON,CARGO,WHLD SANKEY 2401/A. CHASSIS NO 56745 VEHICLE NO 678K45
The ID on the Humber says; TRUCK,1TON,4X4,CT,COMMER 1601A. CHASSIS NO 6310009 ENGINE B60,NO1,MK5 NO 11545
and the tray;BODY 1 TON,C.T. CARGO. ser. CB61009
I dont know what the numbers and letters refer too,I would be very thank full to be enlightened. Robert