I think for you there are four main considerations. 1) Right hand drive? Check! 2) Rust? That is up to you to determine as stated before. 3) Originality? Important only if you care, and you did ask ask about originality so it must be an issue. If it is an issue, then consider the costs to make it right: Paint -- expensive; steering wheel -- if your lucky to find a good used restorable replacement then not too expensive; interior -- I don't think it's an original color scheme (although I like it for a non stock car) and it is expensive to do it right. 4) Engine -- big consideration here -- original, good running order? Very expensive to do over.
So your options are drive it like it is and enjoy or redo any of the areas mentions above.
Above all... have fun!
George