Take it to a gunsmith.
Need the name of the maker to answer. ********* Fluss Stahl is Fluid Steel, produced by Krupp, in Essen Germany. But we still need the make of the gun to answer your question.
No sn data available.
No way to answer without a DETAILED description of ALL markings.
Brno is in Czechoslovakia, Essen is a city in Germany. Two different countries. "fluss stahl" refers to "fluid steel" made by KRUPP Industries located in Essen, Germany. Since Krupp was one of the premier manufacturers of high quality steel products in Germany prior to (as well as after) WW2, there is a good chance that Brno used KRUPP steel to produce rifle barrels. Especially in the late 1930s.
I do not know but will know in a month I put it in a wwII gun auction.
You have a rifle made of fluid steel from the Krupp steelmaker at Essen Germany. That is as much information as we can give you from the information you gave us. A gunsmith should be able to identify your gun in person, but we would need a lot more information to make a good guess- sorry.
Krupp Essen is a large German company engaged in many engineering fields.
A type of rifle made in europe.
Probably between $800-$2000 depending on condition and the grade of the gun.
http://www.novelguide.com/a/discover/ewb_09/ewb_09_03638.html There is alot of history on the Krupp family on this site. Hope ya find what ya are looking for. Widow Krupp acquired a foundry near Essen called "good hope", but later sold it.
Unfortunately, there was more than one company that used the Essex name, The "Krupp" marking was the German steel firm that produced the fluid Steel (Fluss Stahl) used to build the rifle.