I'm restoring a 55 Crown Victoria, with the factory 2 bbl. 272 Y-block. she's been garaged since the mid 1970s and the engine was run routinely until my grandfather passed away in 2001. Since that time she has sat largely untouched. I've spent the better part of the past week reading various classic car/hot rod forum posts on starting a engine which has sat for a long time, and looking through magazine articles and books on the Y-block to familiarize myself with things.

As I'm waiting on the carb rebuild gaskets to arrive and I still need to pick up a new battery, the goal here is to get the engine to turn over by hand and ensure she isn't seized before attempting to start the car up.

This is what I have done so far:
1. emptied the gas tank of all old gas (carb. and fuel pump were unsurprisingly dry)
2. Drained the old oil, it was clean, color looked good, and no clumps or gunk 
3. removed the spark plugs and poured about a shotglass' worth of Marvel Mystery Oil into each cylinder
4. pulled valve covers, and using a new clean paint brush and eyedropper, lubricated the rocker arms, valves, springs, and upper pushrods with motor oil
5. Added 5 fresh quarts of oil (did not replace filter I intend the flush and change the oil again once the engine runs)

After about an hour (not very long, I know) I put a socket up the the bolt on the Vibration Dampener and attempted to rotate the crankshaft my hand, but could not get any motion. I didn't use much force, I didn't want to force it. My suspicion is that the piston rings might be stuck, some rust from humidity, that or some part of the valve train is stuck having sat for so long without oil as it had seeped it's way down to the pan.
Tomorrow or Tuesday I plan to try again, so my questions here are:

a) have I done everything I should have?
b) is there anything else I should do?
c) is there anything I should look out for?
d) how forecful should/can I be trying to turn it over?
e) if I get it to turn over completely a few times, would it be safe to start the car?
f) is there any questions I should have asked here but forgot?

I'm fairly new to auto resoration, so I'd appreciate all the feedback I can get.