1969/early 70s Carlton Corsa-derailleur hanger problem

[Ideale]

I have a frame and forks and what seem to be to be original wheels-I need a derailleur hanger which allows the wheel to sit far enough back in the dropout.What would work?
Oh yes-and seat-post size?
Thanks for help

 

[Midlife]

Which rear mech are you thinking of using? 26.8 rings a bell for the seat post size but it's Friday night and have had some lager lol.

 

[Spokesmann]

A Huret Svelto was original equipment, but a hanger equipped Shimano Golden Arrow works - I use one on the same model. A hanger equipped Simplex Prestige would be OK too. Any hanger equipped mechs of the old school type should be OK.