It probably is what is left of a Colt. It looks to have been polished to within an inch of it's life and than refinished. There are no sharp edges left, no roll marks and everything looks smaller, thinner. Even looks like the screws stick out too far because the plates that they hold in have been buffed thin. There were some Colt look alikes built in Spain in the early half of the 20th century, quality varied widely from very poor to barely adequate, probably more were knock offs of S&W models than Colts.