I must have had a moment of brain freeze, 5598 is not two numbers off 6000 but two from 5600, sorry guys Gary

Thanks for those two new pictures Gary. That new picture of the barrel flats is much clearer and the 'keyed' hinge pin is evident in that picture of the frame.

Gary/Dean, Just to note some differences between 5598, and my 5868, there are crescents above and below the serial number on the water table of 5868 and 5 / 11 barrel weight stamps just forward of the barrel flats, a D for damascus on the right barrel and the number 12 on the left barrel. The "12" seems odd because the gun is a 10 gauge.

Very interesting Austin - can you post a picture of the barrel flats for us?

Dean, I ant you to try something for me, when you double click and triple click does the image get bigger by 2-3 times as mine does when I do that, It makes the barrel flats take up the whole screen, Gary

Dean, I'm still in the photographic stone age,( think 35 mm film ), but I may be able to get my wife to shoot some digital's for me. Then we have the problem of posting them. Last year Chris T. was kind enough to post photos of my 16 gauge Trojan for me and perhaps he'll help out again. I'll try to get some pictures taken so that everyone reading this thread can view them, but if this does not happen I will have the gun at Ernie's.

Got to be getting close to the demarcation line. Perhaps we can find "the first and the last".

Dean, Your gun # 5711 has got to be pretty close to the earliest known with the recessed hinge pin. I would submit it to the Parker Pages to start a new catagory.

Thanks for the suggestion Austin - I may just do that.
Best Regards, Dean