Yeah, I agree that 60 could be fat. Plug should be dry and tan after running. If it needs rebuilt, though, and she smokes alot, all the time, crank seal would be worn. Then she would be sucking oil and giving you a rich reading on the plug. If you can start it without boots, it needs a top-end. The right thing to do is pull the top-end and check your cylinder plating, piston condition. There's an excellent post on piston color and appearance reading, just like the one on spark plugs.
You should be able to get the power valve cover off, and watch it work. When the engine revs, it comes out like an inch. Sometimes carbon and oily goop hold it up and choke off the power. Usually you can get it free, but its full inside. If its just a little stuck, you may be able to go rippin' and help it. I'm guessin' its that powervalve, or if she smokes like a smoke bomb, then its crank seals.