If the extractors on this gun are split in the same fashion as on an ejector gun, then please post some pics of those barrels. I recently came across another Field Grade FW 16 gauge from 1915 just as you describe above in the low 400XXXR serial number range that featured a set of 30" ejector barrels? The forend on this gun was the push button type and squared on the tip to accommodate that device; however, the push button mechanism had been removed and the hole professionally plugged. The fore iron attachment was the typical "J" spring type found on Smith guns; and the iron was fitted with ejector kickers, which were flush with (not raised above) the surface of the iron. There was also no "banjo" style forend escutcheon as is normally seen on auto ejector Smith guns from this period. Between the barrel flats and fore iron hanger was a device consisting of three small square plates, two springs, and a rod (best description I can provide). All component parts featured the same serial number, and all stampings were of the same size and font style. I can't imagine how this device worked, or even if it did; but my wildest thoughts were that this may have been a factory attempt at auto-ejectors using a push-button type forend? May never know, but this work was done professionally. This gun felt very light and had been after-market converted from a pistol to straight grip; so who knows the extent aftermarket work that may have been done, but I tried to buy the gun just to take it apart to understand what all had been done. But alas, the seller was unwilling to take less than $500; and I was unwilling to risk more than $300 (figured I could get that much for a set of ejector barrels in a worse case scenario). And for whatever reason, this gun still intrigues me.