Check your wiring. The Stihl 056 wants a wire connected to the top right screw holding the clutch cover in place. Sounds goofy (and it is bad design), but it's easy to leave that dangle and then you will have no spark. I've had several come into the shop that way with no spark. Also, the tank housing has to be disassembled to obtain access to the ignition switch (another lousy design). That switch could be defective. I've also run into 056's where the ignition wire that connects the tank assembly to the cylinder head was broken. Check that also.
I believe the last time this saw was manufactured was in 1991.