Went into the local gun shop today to pick up some ammo, and found a strange little Mauser. It has a 18" barrel, is stocked all the way to the end, has no markings at all except for the serial No. and .308 stamped on the side. Looks like a 98 action,and has no bayonet lugs. Last but not least, the sling hooks up on the side so It's for a mounted person. It looks very much like a spanish carbine, but all the spanish carbines I've seen have normal sling mounts. Any idea's?