Certification Issues etc...
 

I am writing a story/novel type thing (for my own entertainment - I'm not daft enough to see myself as a budding Gann or St Exupery).
I'd like to make it as believable as possible, though - and I'd really appreciate your help with the following questions, please;:ok:
i) Would it be possible to register and operate an aircraft type which has disappeared from the G-xxxx register,either commercially or for humanitarian purposes (e.g. a DC-7, 707 or Viscount?)?
ii) In a similar vein, would it be possible to operate a foreign-registered aircraft from a UK airport for similar purposes without having to type-certify and/or re-register it? (I couldn't quite swallow the concept of a G-xxxx registered IL-18F...) If so, would the aircrews have to be from the country of registration or could pilots holding UK commercial licences fly them?
iii) Are the the Lockheed Hercules and Douglas DC8-7X type-certified for UK Civil operations? If so, which models, or is it a "type-wide" cert?
A boring subject,:8know...but once I've got over this hurdle (with your kind assistance), I can get on with the stuff which really gets me going - being up in the sky!