Don't know, but I have one with an eagle instead of a horse on the grips.
The Bull logo and Marca Registrada were used in Spain by the firm Gabilando. They made a tiny top break revolver is 6.35mm (.25 ACP) They were made for only a few years- about 1910-1914.
The name was a trademark used by Fred Bifflar Company of Chicago. The guns were made by several different factories, only a couple of which are known. The Spanish wording points to the unknown manufacturer in Spain, most likely in Eibar, where many companies produced inexpensive firearms under a multitude of trade names.
It might be eaiser to ask who in Beligum didn't make a revolver.
In the USA
Samuel Colt
Serial number shows it is a single action revolver made someime after 1978.
In the USA
Many were
Samuel Colt invented the revolver in 1836
38 cal colt's revolver sn 94764 what year was it made?
You will have to be more specific.
Not much.