Roughly 50 psi with decompression; about 140 without. Cold valve lash should be 0024 to 0055 intake, 0043 to 0075 exhaust. There is no way that you have too much compression. The piston does not create a vacuum, aside from pulling the air/fuel mix in. Your starting issue is likely a carburetor...
The Tohatsu 40, 50, and 60 are all in the same family. Kits are available for many years after the motors go obsolete. In fact, I am repairing a 1986 90 hp unit right now. Evinrude never made oil.
If your bearings are that loose and the oil strainer/pump/sender are good, it's time for new main bearings... Since the conn rods don't use bearing inserts, check those clearances. Might be time for new rods as well.
Please remove the link to the illegal FSM. They are copyrighted, and Tohatsu may sick their attornies on them.
Forget seafoam. It's just mineral spirits. You can soak all non rubber bits in real carb dip overnight. You can get that in 1-gallon cans at the auto parts house.
Occasionally a kit...
The B came out around 1998. In North America, that was followed by the 4-stroke motors. Yes, the A is quite obsolete. No water pump kits, and no carb kits, etc. Probably uses the Tohatsu 2-stroke fuel connector.
All these 2-cylinder Tohatsus (both the old 2-strokes and the newer 4-strokes have a dual output siamese coil, and use wasted spark. One trigger, one ground, two HT leads.
Yes there are o-rings. It needs to greased well. Might have gotten salt in there. If it turns, you can pull it out with vise grips and a lot of wigglin
