What was the first saw you stripped right down and completely rebuilt and how did it run? Do you still have it? I grew up in the boreal forest region of Ontario where paper mills were the main industry and the early saws that appeared in the bushcamps were IEL Pioneers , then 450 and 650 Pioneers. D44 McCullochs were popular as well as some Homelites and Remingtons . I had a 650 Pioneer given to me in a box and it was fairly complete so I stripped it right down, cleaned everything, replaced what needed replacing, painted what needed to be painted and put it all back together. Ran like a big heavy Swiss watch, consistent idle and would pull the chain on its puny 16" hardnose bar through anything. Paper mill wanted black spruce and jack pine which were seldom more that 12" in diameter, so why sharpen more teeth than you have to? Unfortunately, about 5 years later, my house was broken into and thieves made off with it as well as a D44 McCulloch I had recently rebuilt. Hope he found out the hard way what kickback is.
that was sold used as runs perfect. Not, base gasket was ripped and top was scored. But did run somewhat. 
