For starters, it's not uncommon; I don't know much. A few years ago, my austrian relatives sent me these pictures of my Great grandfather's war medals on a cushion.
What I've gotten to know during the last few years is that he served in Norway but apart from that, not much (information comes slowly and dirty looks are given when you ask too much questions).
So that's why I'd greatly appreciate if anyone could help me shed light on what we're seeing on that cushion. I've already Identified a few things like the infantry assault badge but some are troublesome like the big golden thing on the left (probably something involved with Austria).
There is the Narvik Shield for the participants of the famous Battle of Narvik, which started the German invasion of Norway. Commander of the operation was (later Generaloberst) Eduard Dietl. It seems like your Great-Grandfather was part of the Gebirgsjäger-Regiment 139 (Mountain Infantry) which was later named after Dietl, which also explains the green ribbon: "Generaloberst Dietl". The small badge under the Narvik Shield says:
"Gebirgsjäger Regiment 139 - 1995 - Last meeting (of the regiment)"
probably where the veterans of the regiment met a last time.
The Cross on the left is hard to identify. It has some kind of coat of arms on it, it looks post-war though.
EDIT: I think this might be it: Großes Ehrenzeichen des Landes Kärnten
hard to translate, but something like this (Grand badge of honour of the state of Carinthia)
A few I could identify:
Ritterkreuz des Eisernen Kreuzes:
http://www.lexikon-der-wehrmacht.de/Orden/ekrk.html
http://en.wikipedia.org/wiki/Knight%27s_Cross_of_the_Iron_Cross
Verwundeten-Abzeichen
http://www.lexikon-der-wehrmacht.de/Orden/vwasp.html
http://en.wikipedia.org/wiki/Wound_Badge
Infanterie-Sturmabzeichen (Silver)
http://www.lexikon-der-wehrmacht.de/Orden/isa.html
http://en.wikipedia.org/wiki/Infantry_Assault_Badge
Ärmelschild "Narvik"
http://www.lexikon-der-wehrmacht.de/Orden/s-nvk.html
http://en.wikipedia.org/wiki/Narvik_Shield
Medaille zur Erinnerung an den 13. März 1938
The three badges with the helmet pierced by two blades are Wound Badges. The name Anton Reitterer, in the cases on the right, appears to be a (Jeweler? Company?), which produced Austrian medals, all of which I have found to be postwar. Unfortunately, my German is crap, so that's about all I was able to find on that regard. Do you know if your great-grandfather served any time in the postwar Austrian military? It might help.
Looks like there's an Eastern Front Medal as well. http://en.wikipedia.org/wiki/Eastern_Front_Medal
Seems your great-granddad was a corinthian illegal Nazi (before Austria was annected by the third Reich in 1938) that served in the Gebirgsjäger Regiment, which is a light infantry of the alpine or mountain troops.