the gun definetly started life as a type B mauser ,if the gun has been to africa that might explain the missmatching bolt, many guns that have been confiscated by authorities in some african countrys were put aside with bolts being removed and than later sold of with whatever bolts fit the action without any regard to serial numbers the last rifle pictured in LESTER WOMACKS book had a mismatched bolt by coincidence he found it it the states in some other collectors gun, your bolt looks like a typical m98 bolt ,btw is that stock cracked it does,nt look that bad could use a bleaching and oil staining and it migght come back to life ....paul