Fox;
My dad used to have an old two-horse, one row walking corn/cotton cultivator made by the Parker corporation. I would have to dig it out of the weeds to see for sure, may have been Parker, Snow just don't recall for sure. Some years ago I spent quite a few hours in the seat of one of those old hand-clutching two cylinder "Poppin-Johnies". Had a 68 JD 112 lawn mower I was cuttting my grass with till not too many years ago & got it on two steep a slope & the oil slinger on the connecting rod got out of the oil & I locked up the engine. Kept meaning to fix it, but went to using another instead. I have a copy of an old Rifleman article by Capt Curtis which Ithaca sent me about 40 years ago. He concluded in this article that Lefever did build America's "First Hammerless Double", but Sneider built the first self cocker.
