Amir..you don't know what you're getting yourself into with this recently acquired 650B Randonneuse. You should just let it rest in peace in Paris, and give me the address so that I can take care of it when I'm back over there at the end of the month. What with unknown brands, unknown and probably unobtainable rear drum brakes, you really have bought yourself a mess of trouble. Who really needs such worries when you can be out riding on your Zeus?
However if you insist on pursuing this mad adventure I will at least try to be of some help. As you know I showed quite a lot of interest in your frame and had it not been for the fickleness of my internet service suppplier, you might have had a bidding war on your hands.
I never quite decided what brand of frame you actually bought and I'm not sure that checking out rivet hole centres will be of much help as a chart i have put together shows many companies using the same spacing. The lugs looked to be of the style that keeps turning up recently on the List with the "AG" (or AC) cast into the seat-lug, and the rear drop-outs are the type in regular use on such frames and also tandems. I recently acquired four similar frames..all of different brands..and all, thankfully with headbadges and some relics of transfers. One of them had a type of Osgear pattern drop-out, linked with a b/o Cyclo gears boss adjacent. The frame has twin top-tubes..and a transfer stating the frame design to be "Depose". The curious thing about this frame is it's brand, The immaculate delicately pressed and "fielded" headbadge carries in and amongst wildly flowing art-nouveau swirls the name "Star-Fling". Underneath it says "Marque Deposee ' JML" Your frame could be one of these.!!!
On your earlier question about drum-brake manufacturers I recall that Sachs in Germany made such hubs as did Perrin-Pelissier in France. The latter is the more likely for you as Pelissier was a major supplier of hubs to most manufactirers in and around St Etienne.. But I seem to remember that the firm "Tank", in France also made such brakes in the 20/30s. I have a 50s Cazenhave Randonneur whose CLB cantilever brakes have been removed only to be replaced with a pair of hub brakes. From recollection these are not Atom, or Sachs. I shall know better when I get back to France at the end of the month. Who knows you might find yourself a bargain in my bike-shed.?
On the matter of the difference between "porteur" bikes and "randonneurs" I think it must lie in the head and seat angles and the trail on the fork. From memory again, I think that the three or four porteurs that I have will have shallower angles than my randonneurs...but that might only be an elusion
I might have some old catalogues with specs in for both types of bike so I will keep up my search for an answer. But seriously... I think you need to move the frame on,,,save yourself a lot of worry and anxiety.
Norris Lockley, Settle Uk