As with all things, it is a matter of what you want to end up with and how much money you have to spend. The cheap and lazy side of me would try some soft taps on the valves with a hammer (While they are in the closed position) to see if there is just some crud or rust that will work itself loose. I would probably just give all of the valves a little love tap and then do another compression test to see if there is any change on any of the cylinders. If there is any improvement, I would tap some more and test again. and repeat the process until it looked like the negine had a chance to start.
The second (just as cheap but not as lazy) part of me would pull the heads and take a long hard look to see if they can be used as-is with a little cleaning.
The what-the-heck-it’s-only-money part of me says to yank the motor and do an A to Z rebuild. Of course, one thing leads to another and there is a very long list of while-the-motor-is-out-I-might-as-well do the radiator, engine bay detailing, new motor and transmission mounts, brake lines, u-joints, clutch, trans bearings and seals, and on and on.
Again, it is a matter of time, money and sometimes just plain luck.