The 98-40 is a Hungarian 1935 modified to take German clips, ammo, bayonet, and sling. The bolt handle is turned down and it is stocked to handle as much like a Mauser as the bolt handle location allows.
The action remains more like a Mannlicher with split bridge and separate bolt head; plus a two piece stock akin to SMLE. Those design features were probably built into the factory to the point that it was not worthwhile to just change over to making real Mausers.
There is an article at:
It covers the debate about where in Hungary they were manufactured and gives such production data as is still available. All production was from 1941 through 1944. There ought to be a date code on the receiver ring, and the WaA stamp is also an indication.