As Old-Smithy said, it is an S98 bayonet for the Gew98, adopted for service by Germanyat the same time as the rifle. The bayonet, by it's condition, shortened and very worn grips, is one of the ones that came out of Turkey in the early 1990s. It should fit your rifle and a correct Turkish
scabbard will be just about anything that it will fit. The scabbard's mouthpiece should be too small for a standard knife bayonet to fit, that is the only difference in the Turk scabbards for the cut down S98.
Are there any markings on the crossguard?