A repeat post from Warmoth's TonyFlyingSquirrel has got the answer. For some reason, the Warmoth Pro, I believe comes with the allen wrench. The others don't.
TonyFlyingSquirrel said:
Truss Rod Adjust
Allen Keys:
Bass Necks, 7/32
Warmoth Pro Straight, 3mm side adjust
Vintage Modern, 4mm
Warmoth Pro Angled, 5/16 socket
Only the side adjust mechanism comes with a wrench. A set of metric and US hex wrenches is a great addition to any workbench! (Hey, Christmas is just around the corner and that would make for a perfect stocking stuffer.)