Had These Rocks In The Shed For Years

Hit them with acid. Iron pyrites will readily dissolve, gold won't. Hydrochloric acid is the go.
If you are VERY patient, the metallic sheeen of iron pyrires will fade over a long time. Acid rapidly speeds up that process.

I can answer that, no. The shape isn't of the gyroscope toy, they have two sides and bend in a U shape at the top and both lead to an open end and the other end loops around to make the handle. There is also a bend like two V's right above the handle also. The reason I know is I am looking at one right now that I just gave to my daughter. I remember playing with these things for hours, I think she played with it for about 5 minutes and then put it down and picked up her Nintendo DS


Edit: I think they are called "rail twirlers"

They all look like pyrites to me.

Compare the formations to these under magnification, pyrites form with a crystaline shape does not generally have the multi faceted sides like pyrite.

The best I can tell you is if you're wanting to know for sure, see if you have a county assay office or an extension office with a local geologist that can look at them in hand.