I'll jump in here as I also have a fair amount of experience with reviving long dormant motors. First I'll address what should and shouldn't be done. Suggestions to not start a motor periodically while in storage are well founded if--when starting the motor you simply run it for a few minutes. The procedure that Michael Yount follows is good, taking the car for a long enough drive to thoroughly bring all components to full operating temperature. What you have done by cranking the motor periodically by hand or starter is also beneficial.
I would not be concerned over finding piston tops with caked on carbon as those deposits indicate the motor was never run hard enough to keep the pistons clean when the car was still on the road. What I would be concerned with is the possibility of stuck or frozen rings. I would squirt ATF into each cylinder--3 or 4 good squirts. If you have a compressor good, but if not purchase or borrow a small portable air tank and attach a blower tool with an extended tip. Hold a rag over the spark plug hole to protect yourself and the surroundings from blowback and give each oiled cylinder a quick blast or two of air to spread the oil within the cylinder. Put the plugs back in--they don't have to be fully tight. Let soak and repeat after a few days. A couple or three such applications should be enough to get ATF down to the ring grooves.
When you are ready to actually start the motor I'd leave the plugs out, drape a rag over each plug hole and with a fully charged battery crank the motor until (in 15 second bursts if necessary to avoid overheating the starter) the oil pressure light goes out. At that point replace the plugs and fire it up. It will probably smoke like a chimney but let it run at idle or idle plus a bit. Eventually the smoking will diminish (unless there are already broken rings). When you take it out for its first drive go easy with a light throttle. To give you encouragement I'll relate my greatest success. I did these procedures on a Triumph GT6 that had been stored in a damp stone garage with a dirt floor for 10 years. The motor was completely seized so I could not turn it from the crankshaft front pulley bolt. I had to remove the starter and slowly work it back and forth by prying on the flywheel teeth until it would make a complete turn. That took the better part of a full day. With it ready to start (fresh gas from a remote container and the oil changed) it fired up - fogged up the immediate area with smoke (luckily our shop was in a wide open area with no residential neighbors). It took a number of hours of running slowly before the smoking diminished-but it did. Good luck (not said sarcastically) -- Dave