Hi Paul: I am far from an expert on the subject and I think that you have come to the right spot to find your answers. The chain stay cable guide is not that unusual and is pretty common to those on that period of Peugeot's (French). I would take a very close look to see what the drop outs have written on them if anything to see if that can help with the country of origin, anyway, just in case the seller may have been mistaken. You may have to look really close since there is paint covering it obviously. The seat stays are a common wrap around that I ahve seen on Falcons made in England but I have a tendency to think that this is not a Falcon since they took great pride in their Head Badges and there was not even room for one on this bike Although there seems to be a little "dimple" on the head tube that may say there was a badge there at one time but I doubt it with these gothic lugs ordaining the head tube. You can see a low end example of a Falcon on my eBay store item #13 0367798057.
The lug work on this bike along with that bearing cable guide is something that is very unique and the only reason why I would suspect that it was from a commercial shop rather than a total custom handmade one of kind type thing is that there is indeed a serial number assigned and seems to be one that is a manufactured sequence. I am not sure what to say...I wish you luck and like I said this is such an interesting frame that I am sure that there are going to be all kinds of input from a lot more knowledgable than I from this email string. Congratualtions on owning a very beautiful machine. Sweet
Jim Abt
Wausau, Wi. USA