Info I found from a Google search.Early Brazilian Colt pistols have a C prefix, they should have a Brazilian Crest, and be marked : EXERCITO BRASILEIRO on the right of the slide. They were also numbered on the slide from 1 - 14500
14,500 pistols were purchased by the Brazilian Army. They were selected from the serial number range C188000 - C209000 randomly. They should have the Brazilian Crest and EXERCITO BRASILEIRO on the right side of the slide. They should also have a Brazilian Issue number on the slide (1 - 14500). The year is also found under the Exercito Brasileiro marking on the slide (such as 1937 etc.) These were used mainly by the Brazilian Expeditionary Forces in Italy during WW II. The US Army recovered some of them off of the battlefields in Italy and refurbished them for US Army use.