The last set I punched out involved acetylene amd a 70 ton press, and they were fresh water.

Anybody have suggestions beyond a torch, grade 8 jamb nuts, PB Blaster, and a BFH?

The later K planes have a nylon insert between the pin and the casting. EZ in and out. Earlier I have used a product called Kano Kroil. Its pricy but I have had positive results, way better than WD40 or others

Its pricy but I have had positive result

Any idea what year they started using theese inserts? Theese are on a 96 boat, it looks like there might be a bushing of some sort on the ram end of the cylinder, cant tell on the top end. I just need to get the cylinder off, the long hinge pin can stay in place.

Are you talking about the cylinder end that attaches to the trim tab? We just ordered all new upper and lower trim tab pins. Our upper pins were both bent and the rubber hose type liners were 100% worn thru. I guess 20 yrs is too long a maintenance cycle! The lower pins (w/attachment for the indicators) were also shot. One pin was broken in half and all the rubber inners were also worn thru. This is probably why Mercury re-designed the tabs in the mid-90's to use the drive cylinder type of rubber bushings.
However, I will say that our last run of the year was pretty sporty.