I can tell you as a furniture & cabinet maker that making invisible repairs to NCL isn't easy - especially with a high-gloss finish - but with sufficient practice
it is possible.
In general, the harder (more "bullet-proof") and shinier a finish is, the more difficult it is to repair. That's why I use sanded-in oil finishes and French polish to finish my basses: it looks great and is [relatively] easy to repair
The good news is that successive coats of NCL chemically bond with one another, forming a single, unified, layer - which makes repairs far easier than if your axe were finished with a product that builds in discrete layers, like varnish.
The bad news is that it will be difficult to blend the repair so it doesn't show - especially if the NCL has color in it
.
Do you know whether the NCL is clear or tinted?
My suggestions are:
Contact the maker and see what they can tell you about the finish. Do they repair finishes?
Don't mess with NCL unless you are properly set up: if you have to, work outdoors. NCL is a bi-product of gun cotton and is extremely volatile (a spray booth set up for NCL has to have explosion-proof fans, light switches, etc.).
Practice NCL repairs on scrap before you tackle your bass.
The key to blending a repair into the surrounding area is wet-sanding with well-lubricated micro-abrasives.
Good luck!
