PS, if you want a very durable long term coating then the baked on paints are best. Duracoat, Alumhyde, are just a couple of products. PM me and I can give you someone that does this stuff.
Personally, I like a matte finish in 'working' toys. I sandblast the surface then use matte black spray paint. Laquer or enamel is just fine. The last can I got from Wallyland cost a little over $2 and would do several rifles.
Is it durable? Nope! Does it look good? Yep!
Overtime, the paint will wear. One minute with a sandblaster and I can repaint as good as new. Most of my toys easily survive a summer of use with no real wear.
The baked on finishes also wear and when they look grubby, you also need to sandblast them. Some pretty agressively.
I prefer to do it myself and pocket the coin.
Jerry
PS there are now more durable epoxy based spray cans. Some are pretty durable for a spray paint.