Hello,
Première Parade was written for 1 solo accordion and for an accordion ensemble of 4 accordions plus an accompaniment. I found it in a catalog of Arrangements Spéciaux pour Sociétés d'Accordéon from Editions E.BASILE, which must date from 1966 (I was about ten when I played this). The duets and trios are well separated. I've been looking for scores of these special arrangements for some time, to play them with the accordion ensemble at our music school. Many scores have been lost. What's more, the catalogs of the time are not dated. If you have scores labelled first voice, third voice, put them on the site, I might be able to guess the second voice. I have the same one for accordion solo as the one posted on PA.
Sincerely
Gérard