Need help identifying my rifle

[krinko]

The 98k has an integral handguard ring at the front of the rear sight base. Like this---



To fit the long handguard as is shown in your photos, one of two things has to be true.

1.A relief cut has been made in the long guard to hide the retaining ring inside it.

2.The retaining ring has been ground off.

Before you spend money on a replacement stock set, you would want to find out if the answer is "2.". Any restoration from that point would require a replacement front sight base.
-----krinko