There are all kinds of ads in ohio for new saws that are all knockoff saws. In general if it is a clean saw at a good price it is a knock off. Craigslist is littered with them around any large city, that is the first hint.
Be wary of any 360, 361, 440, 460, 660, 070, 090 and any 365/372. There are some honest sellers and there are some dishonest sellers. The knockoffs can be decent saws, but they should be sold as knock offs.
Recently told that the pole saws, 200t and 250s are out there as well, I have not seen the ads for these myself.
Pretty much any Stihl or Husqvarna on Craigslist these days is going to have aftermarket parts on it even if it started out as an OEM saw.