must be made for an american soldier sometimes after WW 2, dont you think so. anyway high quality work and realy the thing you americans call "guild gun".
Josef Leutner in Salzburg must have been a top gunmaker if this is own work. possible he let made some work in ferlach.

what google found
the Dorotheum in Wien http://www.dorotheum.com/en/auctions.html?no_cache=1 had two guns in a auction

16 ga double gun
http://www.icollector.com/Doppelflinte-signiert-Josef-Leuthner-Salzburg_i64006

and a O/U combination gun in 16/65 and 7x72R which dated him busy before WW 2
http://www.icollector.com/Bockbchsflinte-signiert-Josef-Leuthner-Salzburg_i64036

here is a short thread about Leutner on shotgunworld
http://www.shotgunworld.com/bbs/viewtopic.php?f=5&t=216880

Sauerfan who is very knowledgeable dont realy know him, ok he is more in Suhl made guns and rifles.

this is intersting for you, a 98 k sporter from Leutner
http://forums.gunboards.com/showthread.p...ase-PICTURES-UP
could have stand side by side with your springfield in his shop