The parts interchange 100% with a "real" Mauser, so I would call it one, anyway. They generally are recognised as one of the finest Mauser variants.
When the Kaiserliches Waffenprufskommission selected the (let's be honest) Mauser-based Mannlicher rifle in 1888, Paul Mauser was standing there with his nose a little out-of-joint because they had refused to select HIS latest design. Well, everybody was trying to develop a rifle overnight which would handle smokeless powder ammunition, and one of the countries most desperate was little Belgium. So Paul Mauser sold his latest design to the Belgians, who called it the Model 1889 so that they had a NEWER rifle than Germany. But the Belgians wanted to build their own rifles, so a bunch of Belgian gunmakers got together and started the FN, the Fabrique National d'Armes de Guerre: National Factory for Weapons of War. They built a factory and took a licence from Mauser to build the 1889.
Later, as Mauser made one improvement after another, FN started using the improvements until finally there was a huge great amount of screaming and cursing and everything went to court and finally the shrieking quietened down and an amicable agreement was worked out under which FN would be allowed to rent certain Mauser improvements. FN, at that time, was no big competitor.
Things changed, though, after World War One, when DWM was broken up and Mauser was allowed to stay in business solely because they had a small plant and were making sporting rifles. They were not allowed under the Versailles Treaty to make military rifles at all. Suddenly, the agreement with FN became a Very Good Thing. FN made Mausers for export in Belgium and, just South of Germany, there was Czechoslovakia, which had been GIVEN a huge arms industry made up of German equipment, making Mausers for export. So the one served as a counterpoise to the others and the biggest competition seems to have been in pure quality. The 1920s and 1930s were definitely the high-point of 20th Century smallarms production.
An FN 7x57 Venezuelan in MINT condition? Grab it! They ain't makin' no more of they and they are damned rare to start with. Repeat: grab it! If you don't, somebody else will, just as soon as they read this.