CAA approval will be the stumbling block – can’t you use an in-country partner supplier of the original plane manufacturer?
What plane is it if you don’t mind me asking?
How quickly do you need it? Because this task has “University Final Year Major Project” written all over it, and you’ve just enough time to get it submitted.
You could go to a Uni. with an accredited BEng/MEng Aerospace Engineering course and get a tie-up.
The student could then work through the CAA regs as part of the work. I did something similar for Pilatus (Switzerland) in mine, for in-flight testing.
There were a group of students building a GA aircraft from scratch as part of their major project & eventually it was to be pushed through to flight.
Hertfordshire, Manchester, Salford (maybe, if it’s still going!), Loughborough, etc might all help.