Hello
Here is the information captured in the database of the SACEM.FR.
BELLE DES VOSGESSong ISWC Code : T-004.850.806.0
RIGHTSHOLDERSITHUBERT LEDENT, Composer IPI Code : 401704114Bernard MARLY, Composer IPI Code : 65016990MICHEL TORELLI, Author IPI Code : 152622100FABRICE PELUSO, Author IPI Code : 148620080
There is no mention of a possible publisher. Either there is nothing, or self-publishing in a number ultra limited to the rights holders.SolutionsSee for each rights holder if he has a website on which possibly the score would be offered. If it is not the case, write to him (if he is still alive) or to the heirs.
And at worst write the music.