Should fire up with fresh fuel. When you get your fresh fuel, add Sta-Bil to the can before filling along with 1 oz/gal of Marvel Mystery Oil. Double the MMO for the 2-cycle in addition to the regular oil mix. 2-cycle oil has had fuel stabilizer in it for many years so you might get lucky there. In this case it might turn out to be good that they were stored fueled, considering the stabilizer. Let us know what happens when you try to start them. Another thing you can run into is rodent/insect nests in hidden places in the equipment. Check all air filters and look things over with a strong light before working on them.

After that many years, I'd definitely use fresh gas. Stabil can only do so much.
IF the old fuel doesn't "seem" too bad, you can dump it in the car. I probably wouldn't mix more than 5% at a time though.

Spark plugs should be good.

I'd at least try to get them running before changing the oil.