The answer to their value is that they are not worth insuring. They may have been bought the first time for $100 or more depend on how retail they were, but you probably couldn't sell them for much, although they do have excellent luster. Except for the 10k gold clasp, which is unusual to put on pearls assembled in America, fw pearls, I would bet they were considered high quality, when sold. I think they are of very good quality in every way but perfect roundness.
Of course, I am well known for my love of fw pearls, but I do love that one. You could wear it a lot and with jeans to concert clothes and it will be very durable and forgiving of everything except cosmetics, perfumes and hairspray directly put on them.