Dear gun lovers!

My brother asked me to find out a manufacturer of the gun he inherited. Although, I love guns but I am not a specialist this culture. I try to share the link on my Dropbox where I have photos of the rifle (can try to use another server).
I deduced only that the gun was fabricated before 1939 in Germany. I honestly could not find the mark of the manufacture in the internet. The main purpose of this research is interest, the second purpose of it is the value of it.
I hope you could help me with this.

Thank you in advance!

Andy