Regarding this document shown in J.C.Fayer "Vols d'essay", the Folland Gnat, the Avro 727
and the Dassault Mystere XXVI (led to the Etendard VI) were considered.
I can add the ill-known SIPA S.800
My complete lits, the, is:
Avro Type 727
Breguet Br.1001 Taon
Dassault Etendard XXVI
FIAT G.91
Folland Fo.141 Gnat
SIPA S.800
In the same timeframe, but not directly answering the NBMR-1 there were the:
Aerfer Sagittario II
Bpulton Paul P.111A
Nord-SFECMAS N.1402 Gerfaut
Nord-SFECMAS N.1502 Griffon
Sud-Est SE.212 Durandal
Sud-Est SE.5000 Baroudeur
Sud-Est SO.9000 Trident and probably some others...
Nico S