I know there is a CD somewhere which has naturalisations on it. In the=== No Stellmann among the naturalization files I used for my researches
concerning French jewish naturalizations during the nineteenth century
(1815-1900), but as it is not a very specific jewish name - and as I
selected the files by onomastics in chronological books of all the cases
treated by the department of Justice that was in charge of it at this time -
I may have missed it.
Other question. If they married in the Tournelle synagogue, they probably
the same day, or the day before had a civil wedding in Paris too, with
precise places and dates of birth. Did you ask for it? As the wedding was
in 1881, you will now find it in Paris Archives, Boulevard Serrurier. They
usually don't make researches or send informations by mail, but some one of
the CGJ could help you.
CGJ - Paris