I generally prefer to use an airbrush but there are exceptions. If it’s a small area that needs to be restored, personally I’d go with a decal then clearcoat over that. Airbrushing means you’ll need to colour match which may or may not be a simple task. There’s also the finer detail that comes with a decal that may be harder to replicate or produce with airbrushing

Any time you can paint, paint. If he is skilled with a brush, you will have much better results.

I’d go decal. Color will likely been more of a match. Plus you’re clearing it.

Assuming the artwork and colors can be matched painting is always the better option.

Search through the restore threads. I've seen very taleneted brush and airbrush work and excellent decal work.

I'd say go with what's in your wheel house.

Painting isn't hard either. It takes a patience, a steady hand and very small paint brushes.

I had to use waterslide decals on the more complicated areas of this restoration, I would have preferred to paint everything but my skill set prevented that.
https://pinside.com/pinball/forum/topic/polishing-up-a-silverball-mania

Sadly I don't know, it was sold shortly after those images were taken.
However since everything was clear coated with multiple layers, I can only imagine they would be holding up just fine.
Yes, they were all laser printed.