I had P4, sold it in early 2007. Peter told me it was the only red one made. The main difference from the final production was that it didn't have a ch 2 low/high gain switch.
I'll take it if you'll throw in a bottle of Louis XIII, a Baccarat Crystal Perfection Cognac Glass, and a box of Gurkha His Majesty Reserve cigars to sweeten the deal...
i'm not sure but peter had one at tone merchants back in the day that was not a red faceplate, and was loaded with 6550s, and i don't think it even had a headshell, and it was being referred to as the prototype herbert. it was scary loud.