Hi Seamus,
For a bit of history, go to the following website and just enter 39YX32 in the first box, you will have a charge for the search and receive a copy of a Key Card, this will havea number of vehicles listed, yours being one. The reg number was allocated after 1949 and the card will show the wartime number (not sure if the one on the door now is authentic), also when it was disposed off, occasionally there may bea remark indicating the last holding unit. Also the Contract number is shown.
https://www.rlcarchive.org/VehicleSrch
regards Richard