Selection of munitions- please help identify

[manifestdestiny]

Hello y'all,

      I will start off by confessing that my knowledge of German munitions/ordnance is elementary at best, and I apologize if these questions as simplistic in nature.

 

I was given a box of inert shells/casings a few years ago by a manager of the restaurant I worked at in college, and these are some of the objects that I think are German in origin.

 

I am fairly confident that the largest item is a 20mm shell, and I do believe that one of the other ones is a mg42 round, but I could be completely wrong.

I also believe the the spent aluminum casing is from a flare gun. What is the other aluminum shell (another round for a flare gun)? It has a plastic tip.

 

Finally, could anyone help me out with an approximate value of the 20mm round as well as the complete aluminum shell?

 

Thank y'all