It's not a junk gun. Clean it up and use it. It is effective for close range.
HISTORY OF THIS TYPE PISTOL
The original vest pocket was introduced in 1906 as the Browning Baby pistol; however, the "Baby" designation refers to the post-World War II model. The original model is now referred to as the 1906 or the Old Model Vest Pocket. The original model did not have the side safety. After the side safety was added, the pistol was referred to as the Triple Surete model because this pistol seems to have been designed to be carried cocked and locked - locking the trigger, the slide and the hammer. Widely imitated and copied, over 1 million were manufactured by F.N. (FABRIQUE NATIONALE D'ARMS DE GUERRE HERSTAL BELGIQUE). More than 500,000 were produced under license by Colt, and more were produced by others.
ABOUT THIS PISTOL
This particular vest pocket pistol is likely a Beistegui Hermanos BULWARK. It is a 1920s all-steel knock-off/copy of the .25 caliber Browning M1906, an internal hammer semi-automatic pistol called the 1906 or the Old Model Vest Pocket. It has "Spain" stamped on the right side of the frame, and "Automatic Pistol Cal 6.35" on the left side of the slide. The left side of the frame has the serial number. There are NO other markings on the exterior except for the "S" [safe] and "F" [fire] for the flip-up safety on the left side. It has a 2-1/4" barrel that twists to remove. On the interior, all parts are match-marked for the gun with a number that is repeated on all parts. It has a 6 shot magazine.
There are no proof marks on the gun. Although the first Spanish proof house was established at Eibar in 1844, proof marks were voluntary up to 1923. After 1923 they became compulsory. So, with no proof mark, this pistol is pre-1923.
Remove the magazine, then CHECK THE CHAMBER TO MAKE SURE IT IS UNLOADED.
With the pistol in your right hand, use your right thumb to rotate the safety lever towards the slide. Using your left hand, push the slide back (to the right) completely until the safety hooks into the slide and holds the slide open (there is a small notch that the safety tip engages). Now, put the pistol in your left hand. Using your right hand index finger and thumb, grasp the barrel and rotate it 90 degrees to the left (CCW), then pull it outward (to the right) about 1/2 inch or so, then rotate it 90 degrees to the right (CW) to its original position, and finally, pull it outward (to the right) and free. Again, put the pistol in your right hand. Using your left hand, hold the slide back, move the safety lever away from the slide (make sure the gun remains cocked - do not pull the trigger), then move the slide and spring forward (to the left) with a little pull. That is it.
Assembly is the reverse of the preceding.
ABOUT THE MANUFACTURER
Beistegui Hermanos S.A. (BH) originally from Eibar, Spain, is a Spanish bicycle manufacturer founded in 1909 to make guns. In the early 1920s, it began making bicycles and sponsoring cycling teams. The Beistegui Brothers (Juan & Cosme) that made this little pistol also made a Ruby (Model 1914) for France, and, they made many revolvers as well as auto pistols and a select-fire Mauser Broomhandle copy mainly sold in China. Their arms factory was destroyed in a fire in 1937.
Magazines are available from Triple K but they will likely need some filing to work properly. See here: Gun Holsters and Gun Magazines by Triple K :: BROWNING MODEL 1906, .25ACP, 6 RD:
Reproduction grips with the correct logo can be acquired from Vintage Gun Grips in Casselberry Florida, see here: Bulwark .25 Pistol