Thank you all for the information in the previous replies.
Alright so, that large mystery mac has had a presence in the back of my mind for several days. Even though I'm skeptical of it because of its outward condition, I've had a strong gut feeling that it was a deal I should be pursuing. So I did.
It turned out to be a somewhat fruitful opportunity, because the guy had more saws that he was getting rid of. In total, I came home with four macs for $160.
Here's the breakdown of what I know from giving things a quick 10 minute look over since I got home.
Big saw: In better condition externally than I thought it would be, although there's a chunk of material missing near the air filter. Appears to have the numbers 1-71 811 on the bottom. There's also "81" that were X'd out. Turning over the engine by hand does not inspire confidence, compression feels weak. Came with an Oregon 28" hardnose bar that is in really good shape beyond the surface rust.
10 series mac?: Haven't messed with it yet, serious mag rot happening on the bottom, everything else external seems decent. Model 60005.
Mac 300: In surprisingly good shape. Compression feels good and it starts on a prime. Came with a nice bar.
Partial Mac 33?: I think it's a model 33? Something funky happening with the coil and flywheel, it's like they're somewhat wedged together. Also came with a nice bar.
I have to admit, I'm not feeling so confident about this deal. I really wanted the big mac to be a runner, but the weak feeling compression doesn't inspire confidence. How do you remove the muffler off that saw? I need to get in and look at the piston and cylinder.
At the very least, I figure if nothing else I could keep the nice 300 and maybe make some of my money back selling the rest as parts saws if their engines turn out to be junk.
What do you guys think? Good or bad deal?
Some pics
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