Broom Handle WAFFENFABRIK MAUSER OBERNDORF A NEDKAR 1920 SP.Bn. 375

I would like to find out the value and year made of this Broom Handle Mauser... It has the stock and is very good condition. Has 5 Matching serial #s 123535 on it. Has an adjustable sight Guide up to 500yds on it. Barrel is 5 1/2" on it. On the underside of the barrel at the base is KBS8 stamped on it. On the Left side has 1920 SP.Bn. 375. stamped on it back by the hammer & grip. I think Germany (hard to read) is also stamped on left side of barrel. On right side WAFFENFABRIK MAUSER OBERNDORF A NEDKAR is stamped on it back by the hammer & grip.
The pistol grip is wood (walnut color)with a metal ring attached at the bottom (for a strap) very good conditon. The Stock is solid wood and the same color. Stock has a metal push button latch on it. The stock has some worn marks on it(not bad,looks like from being carried), back by the latch on the (door) butt of stock the wood has a split in it and a small peice is missing. Over all the pistol is in very good conditon. I appreciate any info on this. Thanks