Hey Julius, welcome to the forums.
Yeah it takes five real posts for you to 'unlock' the ability to post at Fan Stuff.
It's there to stop spams, but this thread is pretty great. I might move it on over there later on.
I can help you with the cross boomerang. Do you want it to return? I'm not sure you want it out of metal, balsa wood, or just as a decoration.
If you just want it as a decoration, you can carve one out of two balsa wood pieces and joint it together with glue, and paint it metallic.
If you want it to be metallic, you can cast one. I can probably give you the CAD drawing for an intricately detailed one, but it'd be expensive to fly and would not come back (probably, unless I look up some aerodynamics).
However, if you want a realistic, cheap one, that can fly, you can buy this and then paint it metallic color:

It's only $23 (US), so it's actually rather inexpensive. I'm thinking of getting one just for the lulz.
The site is here:
http://www.flight-toys.com/boomerang/indoor.htmI'm thinking of getting one, and reverse-engineering the CAD drawing out of it, and perhaps making one out of a stronger material and putting carvings in it and painting it.