My guess would be most likely an early 50s bike (early RH cranks, stem, early type undrilled Maxi-Cars, Radios 16) that has gone back to RH and possibly had braze-ons cut and modified (would it have originally had a Cyclo RD and Herse front changer?) for modern derailleurs. And then back again to the RH workshop late 70s for the Lily Herse decals. Unless it is a frame unmodified but with earlier parts? Less likely. You can only try to guess. Really difficult to tell from those photos, and without serial numbers from rear dropout and under the fork. Rear dropout on it's own isn't good enough, because there are cases where Herse renumbered the RD hanger when he replaced it. So you get the original year of the bike under the fork, the year of modification on the rear dropout. Maybe prospective buyers should ask for more photos, and both serial numbers?
Alexander March
Bordeaux
France