Okay, key word patience. You rush it, you get to do it twice. Take your time, look at the pics in the manual the first time through,then, open it up an read it.
Yes, the carbs on all sohc 4 s are a PITA to get in and out of the stock box, that is the real reason guys go for pods...which, in itself will be a bigger PITA than taking your time and carefully using the stock set up.
Your rings are probably rusted to the cylinder walls, that's common ( a slipped timing chain would be uncommon).
Top end and valve off, you'll be going with new rings, a nice hone, and new gaskets.While you are there, changing the valve seals, you might as well check the valve movement to ensure they are not stuck too.
While you have the pistons out, switch through all the gears to be sure that the shifting dog aren't rusted tight. you'll hate to do the top end then realize that with just a little extra effort you could have had the transmission working too ( ASK ME HOW I KNOW) yeah there's gears and stuff to look at, to check condition of while you have the cases split too but hey, if your going that far , go all the way and make it right, you already have the gaskets anyways ( while you're there change out the shifter rod seal and any other one that looks suspect). It'll make your next two engines that much easier once you've done one.The thing about a machine that has been in storage is that it wants to oxidize in all the areas that don't sit in oil,so after 10 or 20 years of oxidation things will be stuck . The entire engine and drive should have a thorough inspection to be sure all parts are good , clean, lubricated and in working order before it is ready to go back to work, after all your butt will be on it, kinda makes it worth doing .
Yeah, maybe you could get one of the others to run...I never trust any engine with unknown history, could be a bigger can of worms, you just don't know till you open them up.