Today the official name of Mexico is Estados Unidos Mexicanos, the United States of Mexico. But that was not always the case. After gaining independence from Spain in 1810, Mexico had its share of political problems and turmoil as a Republic of federated states. Sinaloa is one of those states, located on the country's Pacific coast.
Coinage in the Mexican Republic was largely issued by the central mint in Mexico City, but there were many other smaller mints and Sinaloa issued her own 1/4 real copper coins from 1847 to 1866.
Local coinage such as Sinaloa's 1/4 real is a somewhat new subject in numismatics (coin collecting) and the catalogs give values that are, so to speak, all over the map. One catalog I saw quoted a full $1000 US dollars for the Sinaloa 1/4 real, but this is much, much inflated. More reasonable catalog values are:
worn: $25 US dollars catalog value
average circulated (like our picture): $50
well preserved: $100
There is a superb specimen on sale at eBay right now for $50 US dollars. You can see it at this link.
Since Pancho reports that his specimen is harshly cleaned, it will be worth very little.