The problem arises in the fact that Astra-Unceta SA made a slew of 7.65 automatic pistols starting at the turn of the 20th century. A Model 1 doesn't ring a bell for me, perhaps if you posted a clear picture it would help the forum contributors to recognise the Model. Or you could google " Steves Pages " and maybe get lucky. From your description it could very well be a "Eibar " pistol from the 1920's or 1930's, or even a WWI Ruby. No serial number would date it prior to 1935.