Yes dheaton, those blades that you showed in the pictures are #9's but, I've never heard of TWS either.
DON"T throw those #9's away! I'm sure that they don't work very well on any wood thinner than 1/2" BUT, if you ever get into a thicker or harder wood, you will be glad you have them!
You never know, some day you may want to cut a bowl or vase out of 3/4" walnut on the scroll saw and the bigger blades are just great for that. With fewer teeth that clean out the sawdust better and aggressive enough cutting for cutting with the grain on thicker stuff that keeps the heat down they work well.
Fret work is not the only thing you can do with a scroll saw.
Rog