Good stuff Grant, saved me digging into my memory.
The '109 did indeed do a tour of Canada and the USA during WW2, and then returned, eventually, to the UK, being in store for many years at Bournemouth. Some parts went missing over the years, and at one time, the fuselage was covered in signatures, of people who'd donated to War Bonds and similar, when it was 'on tour'.
When restored, it was decided to leave one wing in the original paint, which, over time, had become faded and abraded. The 'diorama' display is, of course, replicating how it looked after belly landing, photos of which are on display in front of the aircraft.
Forgot to add - I think the He-111 fin is off a KG26 aircraft, probably based at Stavanger-Sola, when the unit was engaged in night ops against the UK in winter 1940, to spring 1941.