TOPIC: Mercury Mark 55A - need to free up engine

Along with the boat I recently purchased came a 1959 Mercury Mark 55A
Run on fresh water and usual seller comment of "it ran when we took it out of the water" - it then sat outside for some 7 years or more.
Got it off the boat and first thing realized it was not going to turn over - removed spark plugs and squirted marvel mystery oil inside each cylinder - going to let that sit for a few days and see if it helps. I was able to pop off the flywheel expecting points under there but nothing other than mud bee nest.
I would like some advice regarding:

1. Freeing up engine - tips and tricks
2. Will not shift into gear - advice about that oil in bottom end was very thick and gooey -
3. Is this a magneto or points system and how do I get that overhauled? I am guessing the points etc are at the bottom of the distributor? How do I get to this to clean and check?
4. Advice regarding getting bottom end off to replace impeller and clean out free up fwd neutral reverse

Obviously a lot but I have a feeling that once freed up she might run.

I will post some pics tomorrow

Model number 1522-1567 1959?

lower unit maybe frozen, remove the lower to determine where it is frozen first.

Thank you - just a case of removing the retaining bolts and it should drop down? Lee

there is an allen bolt up in the exhaust snout also. also a nut under the cav plate. and 2 on the sides.

thank you very much - I got the two on the sides and the one below but could not understand why it didn't want to drop down - thankfully didn't apply too much force!

I dropped the bottom section - the prop turns so this is not seized up - I am a bit concerned about the gears though - when I turn the drive shaft and rotate the gear shift nothing seems to change - also when I turn the prop one direction it clicks - I am expecting the prop to turn in reverse when I turn the gear shift part at the bottom - is this correct?

So the engine is seized up - I have been spraying all kinds of release stuff inside the cylinders but no luck with it moving so far - tried my impact driver on it and a breaker bar but no movement - any other tricks to get it to free up? Just hoping the previous owners didn't run it without 2 stoke oil in which case I think I am out of luck.

Thanks,

Lee

Does the prop on the lower turn freely in both directions? At least on my Merc, with the lower in gear, I can spin the prop one way (and it will make clicking noises), but not the other

As far as putting something like liquid wrench in the cyclders. Just a theory, but If you havent already, set the motor up so that it is standing level on it's face. This way the solvent you are using will distribute equally all the way around the cylnder and cylnder walls, vs draining to the low side of the cyclder if the motor is standing up. And, I'd dump in a ton, and then let it sit for a week or more to give the solvent a chance to get to the lower rings on each cylnder.