Gidday Stug (and welcome, I think I recognise that moniker from some of our other NZ forums)

I make no claims to be a Mauser expert . . . so this is only 2 cents worth !!

It looks to me like a standard 98 which has had the military barrel shortened, tangent sight removed, and new sights added, and restocked, somewhat after the fashion of a "guild gun", although I don't think yours is a guild gun.

Does it have any marks on the top of the reciever ??

You may be able to remove the stock by judicious use of heat (or freezing), if you can get the action screws out then putting a set of stockmakers pins in (you can use hardward store bolts of the right size with the heads removed) and giving them a tap or 3 will help.

Cheers
Foster