Thanks for the replies and I guess this is an area of confusion the CAA could clear up.
Having looked at GID 44, I'm of the opinion that I should log the time in the checkout as Pu/t and dual. The wording in the document is...
"Pilot under instruction for the purpose of gaining a licence or rating, or for conversion to an aircraft type within an aircraft rating group or class.
P/UT
Enter time in ‘Dual’ column."
I can sympathise with those advocating P1 though. During this check out, I received ****** all instruction! P1/s would seem more sensible.