It sounds like what you have is likely an old H&R top break chambered for the old .38 S&W cartridge. From what I understand, these were basically copies of the .38 Safety Hammerless and .38 Double Action made by Smith & Wesson from around the 1870’s up until around 1940. Value on such a gun is not likely to be much, considering that even the real Smith & Wesson versions can be had for low prices. Based entirely on a brief glance at online prices, I’d say you’re looking at anywhere from a $100.00 gun for the more common condition guns, up to around $350.00 for a really nice example... perhaps a few dollars give or take.
Post pictures of your particular revolver if you are able to, as I am a relative newcomer to these old guns having recently purchased an old Smith & Wesson Safety Hammerless myself. I may be way off base, and it’s possible that you may have an entirely different model than what I am picturing, but this is my best guess based upon the information you’ve provided.
