Caliber .25 ACP? Looks to be a Colt clone, but I'm not an expert on pocket guns of that era. Can you get a better focus shot of the emblem on the grips?
A google search revealed a possible connection to "Firearms International". You might use that in your search terms.
ORIGIN - SPAIN
CALIBER - .25 ACP
WEIGHT - 13 OZ.
OVERALL LENGTH - 4.4"
LENGTH OF MAGAZINE -
Made in the early 1920s by Gregorio Bolumburu. 1906 Browning style with flutes cut in rear top of slide. Marked “American Automatic,” with a pointed finger on the frame.
"REGINA Tradename of Gregorio Bolumburu on pistols, c.1920. "
I think thats what it is ... im not too sure though
the grips are aftermarket FRANZITE stag repro grips so no help there