Rene HERSE (RIP) Cycles has moved to the US and will build you a brand new "vintage" French randonneur. Gravel racing is the test bed for their products. I'm not suggesting that any Retro bikers should resort to this. But RH does publish a lot of articles on the thinking and design behind this sort of bike. Also if you need tires for one of these they make some nice ones.
I live in the US, so I'm not likely to ever see one of these "in the flesh" much less ride one.
René Herse was inherited by Jan Heine of Bicycle Quarterly/ Compass from Lyli Herse. Jan is a naturalised citizen, born in Germany, who moved to Seattle for academic reasons. I think he is partly French and certainly has spoken French longer than English. I've no doubt Lyli made sure her wider family (she had no children) continued to benefit from the family name financially, but I've also no doubt Jan only had the best intentions. They don't currently supply frames, but they do supply Herse pattern parts, I.e. cranks, brakes, etc at a premium price, but built to last. Somethings like tubing are actually very reasonable, but I suspect they have a vetting process in place. Nothing is made in France any more, but Japan, Taiwan (for the forged parts I think) or USA. The tyres are made my Panracer and owe more to Clement, Dunlop and some small tyre makers I can remember, than to Herse who was a frame and parts builder. They also import Giles Berthoud to
North America.
Jan is maybe a marmite figure to some, too retro or too modern despite his attempts to find a common ground with both. His personal bikes are as close to the original Randonneurs as possible.
I don't belive, nor do I think he would, that Jan is soley responsible for the revival of this style of bikes, but Bicycle Quarterly did help tie a lot of things to together. Same with wider tyres, which he has pushed for over 20 years and now even the Professional Road cyclist rides a 30, rather than 20- 23mm, others were doing it but he put his money where his mouth is.
Gravel/ the revival of off road riding with drops, was going to happen anyway. It was natural people would come to the same conclusions many had before again and
