Tom's comment on the clearly wrong "W" marked handguard/bayonet adapter on the '97 trench in the thread below reminded me of a question I have had for a while. Does anyone have a database that shows, by serial number, when the "W" marked handguards/bayonet adapters began to appear on Winchester Model 12 trenchguns, or an opinion about when they began to show up? They were standard on factory parked Model 12's, but some blued ones had them as well. How early or late did they first appear?