Howdy! I am being offered this 1924 Mexican FN Herstal (Belgium-made) Mauser. However, I need help identifying the precise model and caliber (I suspect it is a 7x57 Mauser). Can I please request your help identifying these variables? Also, how much do you expect this Mauser be worth? P.S. I noticed that the cleaning rod is no longer with the rifle. Is this a major issue for someone collecting it? Is this part easily replaceable? Thank you for your help and I hope you enjoy the picture.