You have a S&W .38 Double Action, 3rd model, made in the 1880s-1890s ers. Over 200,000 of the third models were made, so thay are not rare. Originality & condition is the key to value. Yours has had the cylinder replaced, as it's a different serial number. The plating is nickel, not chrome, and it appears to be mostly there. Value is about $225, give or take $50, at most gun shows and auctions. It is an antique under federal gun laws and does not rquire any paperwork to transfer to an adult buyer, in most states.