I think the best approach here would be to first get measurements done on the paint thickness available, get an assessmnet of the level and type of defects (eg oxidation, swirls, light scratches, heavy scratches, etc) and then you can go from there.
A good body shop/detailer would be able to do this and then if there is sufficient scope to undertake paint correction and defect fixes, they will undertake the needed level of aggression (ie wet sanding, heavy compounds, cutting compounds, etc followed by polishing, sealant & wax applications).
There are many good brands out there that all the professionals use (Menzerna, Zaino, SwissVax, Poor Boys, Meguiars, etc) and together with the right equipment - rotary polishers, dual action orbitals and with the related pads, etc they can make dullpaintwork come alive again.
But it all depends on how much paint thickness (and type of paint) you have to start with
Rgds
Franjo