Porterfield fuselage and wing identification, clues and markings?

[Brett Lovett]

I may soon be looking at a fuselage and wings that could be from a Porterfield 35 or a similar aircraft.  I'd appreciate any suggestions of things to look for on a disassembled and likely incomplete aircraft, to help identify whether it actually is a Porterfield, or possibly a Rearwin Sportster, Rearwin Junior, or even an American Eaglet.  These all seem to bear quite a bit of similarity to each other (with reasons I'm aware of).  I'm familiar with the differences between the completely assembled and covered aircraft, but I'm uncertain about identifying one that's disassembled, and possibly incomplete and/or modified.  

Are Porterfields marked with the serial number, or any other identifying number, on any part of the fuselage or wings?  If so, where are they located?  All of the Porterfields and tandem seat Rearwins that I've seen have the data plates mounted on the wood instrument panel, or the wood panel at the aft of the passenger cabin, so it seems like some more permanent marking would be reasonable, and I've seen similar on other aircraft.  

In the Porterfield 35 model is there any metal structure between the carry-though tube at the rear spar attachment, and the front of the wooden turtledeck structure?  I'm thinking that might be a useful detail in differentiating the models I listed above.  

Photos of an uncovered Porterfield 35 fuselage would also be helpful.  

Thanks,

Brett

[Brett Lovett]

Fortunately there was enough evidence on the fuselage that I was quickly able to identify the aircraft from a photo as a Porterfield 35.  I'm still wondering if there might be any way to identify the specific airframe/serial number without a data plate.