Acoustic Guitar Construction

Just found these items together in a little bag in a dusty (redundant) corner - any idea if they belong together and if so what purpose they serve? There is no screw hole for the socket-head screw. The thicker shaft of the other tool does in fact slip into the female part of the other thingie.
Sorry to be so technical. :-)
Thanks

Easy question: A rocket launching set.

That's IT!!! I've been tinkering and tinkering with this thing in the back yard and haven't been able to launch! Thank you Herman.
Expect incoming over your house in two hours!!

Perhaps you know this already, but the part formerly known as " female part of the other thingie" is a router collet. Looks like a 1/2" collet, so if you were going to use 1/2" router bits, you would replace the one that's currently on your router (probably for 1/4" bits) with this one.

It doesn't need an allen wrench to put it on. A regular box-end wrench tightens it.
I don't know what that other thing is that looks like a top, or why you'd put one into the router collet. The mystery continues...

Thanks dave d - I did not in fact know that that part was a router collet. Now I do, and I think that completes my task of knowing everything that can be known in the universe. Except what that other part is. :-)

The other doohikie might be a centering cone for said router....... maybe

I will see if that works, thanks.