Hi,
This is a very popular revolver here in Brazil.
I.N.A. means Industria Nacional de Armas (National Arms Industry) and it became famous in the 60' for producing for the police, the INA Sub Machine Gun, in .45 ACP, that was a clone of the Madsen. (Very reliable, btw).
They tried to make a revolver, with a reasonable price to the police, so they entered the revolver business. Their products were not well accepted, by the force, specially the .38's.
Since we only had Taurus and Rossi, and imported revolvers were to expensive, the INAs, especially the .32, became very popular among security guards (not police) and civilians, that wanted to have a gun in house for an emergency, but never uses it... , or they were sold as "Saturday Night Specials" (we don't use the expression here, but we had he guns...
)
The sad news are that here in Brazil, they are abundandt, and don't really worth something and DON'T EVEN TRY .357S ON IT !!! Not even +P...
Hope it helps a bit,
Regards,
Andre Tiba - Brazil