Hi I,m thinking of importing a rocket 3 M11 1972 from USA however the frame is a NOS it's has a number on it verified from a BSA dealer would it be posible to get an age related plate in the UK
You need a frame number which can be dated by one of the UK organisations approved by DVLA - BSAOC for example.
What is the US dealer verifying?
If it is not a proper frame number then it cannot be dated.