Hi from Paris,
This link to our "Journal Officiel des lois de la République, (JO)" where naturalization decrees are published, is working properly :
With name "Margolin", you get some replies including "Leon" : I attach pictures of the 2 pages, the one with Margolin, the last one of published list where he is listed, with decree's date.
To get a full copy of his naturalization file,, inquiry is :
"Naturalization file of Leon MARGOLIN, born 1878 July 3rd in Bratolioubovka (Russia), French by decree of 1932, August 21st, published in JO of 1932, August 28th page 9389.
I try to find data for Meites couple.
Archives & history of Medem Center - Arbeter Ring (Workmen Circle / Bund of France)