Hi Pete,
I have asked the question as to this mystery on another forum, here is the response I got..
The answer to the above is that the Boat with the 32 designation is the prototype pinnace built in 1935 by Thornycroft at 56ft in length she was at Ramsgate and went to Dunkirk but her props were fouled and she returned and took no further part in the evacuation,
How does this tally with your records?
Best regards, Clive.