Have your buddy do some research on bringing back old paint. It will look very good if he's careful.

https://www.autogeek.net/detailingtips.html
For the way the pros do it. These steps are the proper way to do it for anyone, but the pros have a LOT more gear and very expensive product.

Here is an old thread showing how a pro did it.
https://www.autogeekonline.net/foru...finish-antique-single-stage-paints.htmlv

Using a 'system' like 3M or Meguier's is probably the best for a DIY guy,
There are a bunch of youtube videos, watch them until you have a good idea of what is going to work for you.


https://www.youtube.com/watch?v=HD7AvQZoYcU
For a hack job, still better than letting it continue to rust,