Many years ago, I bought a military style Mauser 98 (short rifle/carbine length) in 8mm, straight bolt handle, bearing the date 1937 on top of the receiver, under the "Mauser" engraving. Condition appears little if any used, having been since date of manufacture carefully handled and stored.
On the left side of the receiver is engraved "Standard-Modell." Forward of this, on the left side of the part of the receiver that contains the chamber, are four tiny crowns in a square pattern, under the crowns is engraved BG and UN.
The rife is set up exactly like a military German Mauser corresponding to the date on the receiver, including bayonet lug, sling swivels, etc..
It's clearly, however, not the K98k adopted by the German Army for WWII, but it looks like a prototype of it. What exactly do I have?

On the left side of the receiver is engraved "Standard-Modell." Forward of this, on the left side of the part of the receiver that contains the chamber, are four tiny crowns in a square pattern, under the crowns is engraved BG and UN.
The rife is set up exactly like a military German Mauser corresponding to the date on the receiver, including bayonet lug, sling swivels, etc..
It's clearly, however, not the K98k adopted by the German Army for WWII, but it looks like a prototype of it. What exactly do I have?
