PPruNe is a great resource for questions like this. Thanks to all for the helpful and informative answers, which cleared up a few of my misunderstandings.
@Gertrude: You probably have the most realistic answer
. I will need to add a new column to my log to count up the number of bacon butties consumed per trip.
@backpacker/IO540: State of Registry is clearly the key. I hadn't realised the concession specific to N-reg allowing use where you have a local license. So I could fly N-reg here in the UK, but not abroad to France.
@tmmoris/dublinpilot: I'd incorrectly picked this up from the NPPL license restrictions, so no specific pax or power limits apply to the PPL license per se.
@englishall/tmmoris: I found the FAA PPL does specifically limit MTOW to 12,500 lbs. I looked up the LASORS to see if there is a similar weight or pax restriction for JAR PPL but couldn't find any reference.
So I guess in theory, I could do a type rating on the A380, pack it full of non-paying passengers and as long as I keep clear of Class A airspace and obey Rule 5, would be free to overwhelm the bacon butty counter anywhere with a suitable runway.
Anyway, my little brown package with the license arrived today - exactly 2 weeks to the day I sent the paperwork off - so I can now look forward to a wide range of canteen cuisine from airfields around the country.