Nice old top-break revolver. I think I would date it closer to the early 1880s than later in the decade, but it kind of doesn't matter for a specimen as nice as this one.
I don't want to sell an unsafe item, unless the person knows of the problem and is willing to accept the risks.
Thank you for your input on the price of the pistol.
Jerry
Value for insurance purposes? If one like this in operating condition went up for auction, I'd expect it to go for at least $350. Well used top breaks can be had for $150-200, but the price goes up to reflect better condition. It would be worth a lot more than that to you, of course, because of the family association. As to the problem with the action, that could be a spring problem or something else. A gunsmith should be able to put it back in reliable working condition.
(I don't follow these older models as closely as I do the later hand ejector models, so I could be way off on value; if so, others will correct me.)