Yes, a René André 700c randonneuse. Seller in Paris wants around €1100 for it, which is big money for me, but it is lovely. I thought the price would be ok, since no components are needed, but I see it would involve added costs.
I'm in Germany, so my question was initially just about seeking advice. My first language is English, so I end up on English forums. Sorry - now I wish you were around the corner!
Anyway, it seems the job wouldn't be unrealistic, which is good to know.
Steel is pretty forgiving from that era. I'm from the 70's (my cycling era) and stuff like 753 had to be silver brazed at lower temps or it changed character
Vahrona might be a bit cheaper?
Is it something special? Don't see many 3 speed changers on the seat stay