A. Zoli here's some info., I hope this will help you out.
On the bottom of the barrels there is a flat spot, stamped there is the proof marks and in a small box stamping you will find letters or roman numerals, that is a date code telling when the gun was made.
You may also find a small oval with letters in it that will be the makers stamp.
Stamped into the barrels very faintly you may find the importers stamp, mine is "Cape Outfitters".
Left side of the barrels near the breach the barrels are stamped A. Zoli
to the left of that stamp there is R.F.M.- Brescia-Italy-
The barrel choke markings are upper *** lower ****, it is a 20 gauge.
Sometime after Angelo went bankrupt "RFM, Rota, Luciano" aquired the assets of A. Zoli, they built guns marked A.Zoli and RFM. The date code on my gun is 1991 four years after Zoli closed their doors.
If you look on the butt plate there are circles/bullseye or a target moulded into the plastic, A. Zoli's trademark.
My gun is also marked "MICHIGAN DUCKS UNLIMITED"