There's the s/n.
The upper body edge.
And again...
It seems to give the impression of being a bit more substantial than a 4003, partly due to the quality and smoothness of that finish.
Due to the "zero-mod" holes (you can just see one above the treble pickup), I've been thinking about having it refinished; I might do something subtle, like have a two tone metallic which goes from that blue to black.