Two series:

100 vehicles, N 8701-8800 built in 1950 in Italy, later as Z12

50 vehicles, N 8801-8850 built in 1952 in Italy, later as Z12.
Builders:

NUOVE REGGIANE, OFFICINE MECCANICHE ITALIANE S.p.A. REGIO EM. ITALIA

ANSALDO S.A. GENOVA STABILIMENTO FERROVIARIO (NOT SURE)

one more
N 8804 ..... from S.F.S. site :
Unknown number, at Korinthos
8726 between Leondari and Routsi
Ex- 88XX, renumbered to Z13 7135 with 2 buffers on its one side, fore connection between the SPAP original vehicles and the Thessalian passenger cars, which had came to Peloponnese.