Pre 1950s rides of LFGSS: old bikes, vintage rats, classic lightweights

I don't think I've got a definitive answer on that. In my mind, based on modern derailleurs, I'd automatically set it up the way show in your picture. However [1], it has been pointed out to me by a number of old timers that it should be the way @falconvitesse has it. If you refer back to the sales adverts where they are pictured, it's common to see them that way round. However [2], it's also worth bearing in mind that those pictures are often embellished with artist's impressions, it could have been drawn by someone who doesn't know bikes, plus you can't guarantee the builder put it on correctly for the picture either. To confuse things further, they seem to work either way round, so there's always a chance it should be how you've got it!