If you are, to the best of your knowledge, fit and well, I wouldn't bother the GP. (S)He would be within their rights to charge you for the 'check-up' as there is no medical problem that you are presenting for and you are essentially asking for a pre-medical medical. They will not be able to check your hearing/vision against the standards and may not be able to do the ECG and other stuff so you will probably not get the reassurance you are looking for anyway.
Sorry to be so negative
Bob