"just wants to make sure that he's not near any controlled airspace. D&D point out that he's approaching the Liverpool/Manchester complex and to stand by whilst they get him an appropriate frequency to get a transit through that area. "But I haven't got a transponder." says the pilot. From the tone of that reply I got the distinct impression that he thought that if he had no transponder he couldn't get an ATC service."
I would imagine that the dubious tone from ATC related to the fact that he was clueless about his location rather than that he had no transponder.
Clueless about location + no XPDR = potential problem
SB