a friend of mine has a welder hes looking to get rid of. not to familar with Miller welders and was looking for some advice.All i know is its a Miller Welder/generator telebyne continential F163. those are the numbers i got off of it. Im assuming its a big 40 based on my research but not really sure. based on the engine can you guys tell me around how old this might be, if it even is a big 40, and around what its worth. I want to make an offer on it but dont want to lowballl the guy either neither do i want to overpay. Any help is greatly aprreciatated .Thanks