Your pistol appears to have been heavily scrubbed at some point, which may have removed (or made very faint) some of the markings, especially those often not stamped too deeply to begin with. But it is worth carefully examining it for any traces of markings.
To give you an idea of what your pistol probably looked like in a more original condition, here are some images of early Unique vestpocket pistols from Eibar gunmakers Barrenechea, Gallastegui y Arenas ("BG"). Depending which reference you check, they are called the model 1921 or model 1922. This only refers to when they began production, although presumably they were replaced by the model 1924/1925. Since the Eibar gunmakers did not begin using manufacturing year codes on their pistols until 1927 (and not all began then, although BG is known to have used the 1927 date code), determining the exact year of production of pre-1927 pistols is very difficult and often impossible.
Even standardized pistols made by major manufacturers (the Savage automatics, made 1908-1928, for example) were assembled with much more hand fitting than now. These Spanish pistols were built with even more hand work than those, virtually hand built in small factories, so there are variations among examples. Places to look for these variations are in the shaping of the front of the frame, shaping of the trigger guard, how the cuts on the serrations were done (not if they were curved or straight, but how many, how wide they are, etc). There is also a lot of variability in the hand-stamped slide legends -- the exact wording, placement, etc.
The two photos with the notations in Spanish are from a Spanish website about pistols made in the Basque region of Spain.
The pistol in the photo with the holster (which is also the pistol used for the close-ups of the markings) has the original grips and probably the original magazine. The holster is old, but there is no way to determine how long it has been with this pistol.
In the close-ups, the photo of the left rear tang shows the usual Eibar "trinity" of proofmarks from before 1927. Starting the 1927, the "PV" was replaced with a letter code indicating the year of manufacture. The rampant lion seen as the third mark also appears above it on the rear of the slide and on the barrel. This mark indicates the pistol is from Eibar. On the barrel, the letters "BG" can be seen to the left of the lion -- this is the maker's mark for "Barrenechea, Gallastegui y Arenas" (later "Barrenechea y Gallastegui"). These marks are typical for Eibar pistols, but may not appear on a specific pistol (or there may be additional markings, often spurious Belgian-like proof marks).
Many of the various parts of the pistol should be marked with a 2 or 3 digit "assembly number" (this pistol has a 3-digit assembly number) used to ensure that parts of the same pistol are kept together. This was very important given the degree of hand work involved in making them.
Did you notice how many lugs are on your barrel when you disassembled the pistol? These normally have 2 lugs, while the similar MAPF Unique pistols normally have 3 lugs. The MAPF Unique pistols also normally have a magazine safety, while the BG Unique pistols do not (in your photos, yours does not appear to have one).
Is your pistol marked with "Spain" or "Made in Spain"? This could also help narrow the date, although these marks were often added later.