Really Jerry, I can't start to thank you enough for buying up all these French frames which, otherwise I would have bought. First the Haral, now the Duravia! I just watched the Duravia down to the last minute.. thought about bidding.. then decided I would email sceno, the seller, after the auction.. to make an offer,, so to speak..And then you stepped in.. making me $200 better off or at least not worse off..in the pocket. I could have picked up the frame from Paris as I am due to pass through on July 5th.. but it's not to be. I have seen one other Duravia, a later model than this one I suspect, but now, having said that, I am no longer certain.
The frame you have bought is constructed, I think, in the same way as the Mecadural frames of Mercier. If you take off the two headbadges you will find largish holes, deep inside which they are allen key heads. I assume that there is an expander bolt type of internal clamp down there.
The Duravia I saw at the Catholic charity and which I almost..bought, had large square block lugs very similar to the ones used by TVT for their highly successful carbon composite frames in the 80/90s - indurain, Lemond, Hinault, Kelly... just about everyone road them. However the Duravia lugs were split underneath and had clamping bolts passing through small lugs on the undersides, somewhat like the Caminargent style, but neater, although the bottom bracket wouldn't have won many prizes for elegance, nor would the fixing of the rear bridges and drop-outs..
The frame I almost bought displayed quite severe cracking of several lugs around the pinch bolt areas, where previous owners had then tried to fit set grub to hold the tubes in place, two lugs had simply been drilled right through and nuts and bolts inserted. My better judgement told me that the bike was just not safe... and could never be made so.. not with any amount of epoxy bonding material in place to fortify the cracked lugs.
because of the squared - off lugs I had assumed a manufacturing date of around the 60s.. to 70s. after the Mecadurals and the Gnome et Rhones... but having seen your Duravia.. and thought about Caminade's 30's technology that would be easily copied.. I am no longer at all certain.
As to place of manufacture, I'm not certain although there was a sales outlet in Paris. I wouldn't be surprised though if they were made in the Rhone valley, perhaps Lyon, where I have seen other lugged alloy frames, and where there are still engineering workshops doing casting and machining for the cycle industry or what remains of it in France
Then of course there is the CMP frame with its squared-off lugs, its crimped-in tubes... but that's yet another story.
Norris Lockley.... Settle UK.. well at 53cms that Duravia was actually my size.. or near enough