Maybe a 6 pounder, 57mm? Since it is reported as British I can't think of anything that is 2". Unless he was pak'ing german AT up his ass.
(50mm is pretty close).

Then again, I'm not sure why I care precisely what he was using as a dildo. Why they don't come up with more amusing explanations IDK. "I thought I had anal parasites and I was gunna clear em out, but the damn things a dud!"