Yes Derby Aviation did the maintenance on the Don Everall DC 3s.
Don Everall was a coach company based in Wolverhampton - which is where all the people that started Derby Aviation came from.
Yes Toulouse was a tech stop on the ""Long Haul"" flights.
For the Marathons, Jersey was the main destination from several regional airports.
Derby Aviation did work on several other DC operators including the Mann Brothers who I think came from down south. And also Autair !!