It's a refurbished rifle originally made at Steyr. It has a recycled barrel on it as shown by the crossed out and remarked serial number. The WN (eagle) 10 is the date the barrel was originally accepted by the Austrian military, WN is Vienna where it was proofed. It would have originally been chambered in 8x50r. The big S stands for "Spitzgeschoss" or a pointed spitzer bullet which signifies the update to 8x56r, an adaptation with better balistics. That shape of S I believe means the conversion was done in Austria some time between 1930 and 1945. The little boxed mark covering the eagle is one I am not familiar with. You have a decent looking rifle there, should make for a fun shooter. Look up "Ruck-Zuck" for this rifle's theme tune.