The gun was proofed in Liege. It is nitro proofed with fluid steel barrels. At the time of proof the barrels weighed 1.3897 Kgs. If they are not within a few grams of that, they have been fooled with. From the catalog, the engraving looks similar to model 334. This was a mid-level gun. The catalog states it should weigh about 7lbs. I would put it between 1910-1914.
I have no idea of it's value in Greece today. I have seen higher grade Pieper guns from Greek dealers. If you want, I can send you the email of a dealer who may be able to help value the gun. Are you familiar with Epimenidis Platsidakis?
Pete
