I'm guessing someone has modified it to run with a pto... all the ones I've seen in the literature I have and in person have belt pulleys. Does it have a cob stacker? If it does it's a 150. If it appears to never have had one it is a model 149. If it has cob stacker and wagon box elevator (which is basically a long square blower pipe with a spout on the end) in place of a bagger atachment it is a model 151. NH shellers were basically the same base unit. Different attachments is how they determined their different model numbers.