I've gotten a few engines running that have sat for many years. I would not consider running your engine without getting those sticky valves working. As Grigg has mentioned PB blaster is a choice. I've used Marvel Mystery Oil with good results. Use a oil can that has a small enough spout that you can get between the valve springs and to the stem. Squirt each stem, then turn motor over by hand. You should see which valves are sticking. Take a rubber hammer and when the valve is closed give it a good wrap on the rocker arm. It may take a day or two, but if you keep putting the oil on them and turning it by hand with a gentle wrap or two it will free them up. If after a couple days things are still sticking I'd give in and pull the head.
Good Luck Don
