"Values" are a very slippery and hard to pin down thing. For example, the same object will have vastly different values for its insurance value, its value if sold by a fancy store specializing in the kind of item such as one on Rodeo Drive in Beverly Hills or 5th Avenue in New York, and that would be vastly different if it were Mary's Antique and Flea Market Store on Main Street, USA, and that would be vastly different that its auction value in a fancy auction like Christies, and that would be very different than an auction at the Acme Bargain Auction Barn in Anytown, USA, and that would be vastly different if it were being sold to a dealer, and so on. It is not unlikely that the same object that would be valued for $1,000 in a fancy shop with a wealthy clientele but would only be valued at $100 if being sold to a dealer. Or that same item could wind up with an insurance appraisal of $2,000 since insurance appraisals are always the highest (usually 50% to 100% higher).
Estate appraisals provide an even different kind of valuation, which are typically lower than insurance appraisals. Since you have many very nice things, my strong suggestion would be to find a good estate appraiser in your city or state and have them do the appraisals. Yes, it will cost you some money for their service, but it will be something that will stand up to probate, the tax man, and any other heirs if the property is being divided and this is especially important where there are nice things involved.
One additional thought. As to the object that "belonged to Marie Antoinette" you should go on the assumption that it did not. Unless there is very convincing proof - not just family stories or notes from family members or notes from a dealer who sold it to you or such, but actual uncontestable proof that would satisfy anyone who might doubt you should go on the assumption that it did not belong to someone famous and it has no added value because of it. If everything that is purported to have belonged to Marie Antoinette or George Washington or Queen so and so, or any other famous person actually did belong to them they would have needed vast warehouses to hold it all which of course was not the case. Such family stories and myths grow with the telling over the years - kind of like the party game called telephone where one person whispers something into the ear of the person next to them, and they in turn whisper what they heard to the person next the them and on down the line, and the last person announces what they heard to all followed by the first person who started it announcing what they really said, then everyone has a good laugh at how different the two were.