Also, will it correct limbs that have taken a set?

Jim, you can add 10# plus with sinew depending on how much sinew you add. Sinew shrinks when it dries and can draw a bow limb into reflex. It can remove the appearance of set but the damage is there already. You get the most performance from sinew when you add it to a bow with little if no set and let it draw the limbs into more reflex.

I havn't sinewed a bow in years but did a few.And if I bemember right I'd get 3 to 5 pounds per layer.this was with real sinew.I've never used fake.But seen bows that were made with it.
 And I agree with PAT it's best to start out with no reflex.Each layer adds more reflex.And if your stave has to much reflex to start with you may not be able to get the weight you want with because of to much reflex to much reflex.
If your useing it just to add weight.