I have a receiver spotted for a project and the price is right. If it is not an elsie it was sired by one. For all practical purposes it began life as a regular sidelock hammerless frame field grade. It has the the machining in front for the elsie cocking levers and the space behind the rib extension to engage the bolt, but it also has a couple of notched recesses amidships in the water table across the slot for the lug that I can't locate on another shotgun. These look to be a machining cut to activate an extractor link like we see on the Stevens 225, 235 and others of that ilk. Serial number 96XXX with all three patent dates present. Can somebody please tell me what I am looking at?