Greco guitars have been made by Matsumoku, Fuji-Gen Gakki [3], Dyna Gakki [4] and others as well.
Greco Gibson replicas started using serial numbers around 1975 and pre 1975 models had a Greco logo that looked like "Gneco".
From the mid-1970s to the mid-1990s Greco models have mostly used 2 serial number formats for non Acoustic models.
The first format is MYYPPPP.
M = production month (A=January B=February ... K=November L=December).
YY = year (79=1979).
PPPP = production number.
The second format is YPPPP.
Y = year (9=1979 0=1980 or 1990).
PPPP = production number.
Sometimes a month letter is used in an MYPPPP format.
Since the mid-1990s Greco models have used other serial number formats as well.
Most of the Greco open book headstock Gibson replicas were made by FujiGen Gakki. Some Greco open book headstock Gibson replicas starting from around 1988 had no serial numbers. The lower priced no serial number Greco Les Paul and SG models were made by Cor-Tek (Cort) and usually have Cor-Tek (Cort) potentiometers. The Cor-Tek made Greco guitars have square shaped, brick like nuts with no slope and also often have shielding paint in the pickup and control cavities. Other higher priced no serial Greco Les Paul and SG models were made by Tōkai and the Les Paul models have an EG-75 or EGC-75 model number stamped in the pickup cavity and sometimes have fret edge binding. The no serial Greco guitars made by Tokai have square shaped routing holes at the bottom of the pickup cavities whereas the no serial Greco guitars made by Cor-Tek (Cort) have thinner rectangle shaped routing holes at the bottom of the pickup cavities. Kanda Shokai stopped using the open book headstock design on Greco Gibson replica models around the early 1990s and then concentrated on their other model lines and Fender Japan. Atlansia have supplied body and neck parts for Greco models as well. Tokai currently make the Kanda Shokai Zemaitis and Talbo models.
