In general, so-called "parlor pistols" were well made and had fine sights and excellent trigger pulls. Somehow, that doesn't look like it has either. I don't think it is 1870 or anywhere near that old, though I can't really say why. The barrel, hammer and trigger guard look like they came off some other gun(s) or, in other words, out of a gunsmith's or hobbyist's junk box.
Jim