I know this isnt a newer school bike site but I thought I'd share this anyways since it's not an everyday bike you see.
Here is a non serial number proto/test frame that Doug Schneider built back when he started building bmx frames and early decals. It's a black 20' Pro xl frame with different drop outs. His later drop outs had adjusters built in them like my 24" Pro xxl frame that he built.
I will post more pics when it arrives.
Here is a quote from Doug
"It was one of my team guys frame, Wayne Mcabe. it was one of the first frames that i made, maby third or forth. i dont think it even has a serial number. it is still in good shape, it just has some of my first style dropouts. probably a 2004 frame"