If there's no serial number, it's either not a factory WGP body, or it was fly-cut on the side to thin it and/or shave off the numbers. Mic the bottom half of the body just above the VASA. If it's nominally 1", it wasn't milled down, and thus not a WGP body.
The vert feed is, however, decidedly not WGP. Most stock verts had an extruded body with a pressed in neck. The milled boss for the neck makes me think it's either an AKA Merlin body, or... who was it, Air America that did a limited run of vert-feed raw bodies, back when WGP was selling vert body kits for like $350?
I seem to recall the AA bodies had the WGP-style male threads for the feed neck, milled into the body. Unscrew the neck (or look down inside) and if there's no evidence of a pressed in neck, that's probably the body.
Anyway, the milling is pretty much all custom. The front block is, I think, a relatively late model KAPP unit, and the backblock is an older KAPP make. Bolt looks like a Shocktech, and the drop's a Centerflag.
Can's say it's the most attractive marker I've ever seen, but if it works well, who cares?