At first I thought that may be the case as well... but what makes me think against that is that there's the same crackling pattern in the pickup and bridge cavities. It seems like someone went through an awful lot of trouble to paint the inside, when that part will be completely invisible once the guts are put back in it. If it is hand painted, this finish seems a wee bit to "custom" for the price that the Charvels which had this factory finish carried.
Also, I saw a couple other photos of damaged areas on the backside of the guitar where parts of this finish had flaked off. The chips of paint missing were perfect little pieces of the crackle pattern....like pieces of a puzzle missing. It doesn't seem to me that a solid painted on finish would chip so "linearally" (not a word?).
Perhaps I am wrong, and the finish is indeed painted on....I guess I'm only wishing for any easy solution to recreating that.
So, if I were to try painting something like that, does anyone have any suggestions about how I might get such thin black lines in between each piece of the white? Would I paint it black first and then just carefully stencil each piece of the top color on? I have plenty of experience when it comes to painting, I am an oil and watercolor artist, but I'm very new with experimenting on guitars. I have only done simple refinishes with stain and clearcoat, I haven't tackled graphics painting yet.