Alright, time for an update.
I was cutting some dead pines with the good saw, got it tuned really well, got the chain sharpened right, and the oil mix figured out nicely.. man is it nice for bucking now, the weight of the saw is exactly right, you don't have to hold it up, and you don't need to push on it either... a 6" piece gets cut in a second.
Now of course that's not good enough
I was speaking to someone far more knowledgeable than me, and he gave me some pointers on what some better port timing numbers are, so I had a jug with a little scuff on it, and a less than perfect piston. I also have an old carb I'm going to work on overboring especially for this jug. Then I'll build a muffler from the ground up, dual port to try and keep the noise tolerable but not choke the saw either.
Also working on a friend's 480 (same basic saw with a new body and 77cc P&C), I've got it running so far, but need some rings before it'll work right.