I recently picked up an Ithaca flues 1 grade (due to the 1 stamped on the water table)20 gauge with twist bbls. Per the serial number I believe it was mfg in 1910. The barrel flats do not show the twist pattern. Did Ithaca build some of the false damascus bbls? Or has the barrel flat been polished to a degree that the twist is not evident? Sorry that I did not take a picture of the barrel flat and water table. I will do so when I get a chance. Thanks in advance for any information. Is there any Ithace doublegun BBS?