Being probably the only ones in existence, would make these Gold bars #heritage items . https://goldassayantiques.blogspot.com/2022/05/mt-morgan-early-gold-history-gold-was.html http://geoscience69.blogspot.com/ These four were all 4 ounces and a bit more. Mt Morgan Mine Antiques from the years mainly 1885 to 1932 when Flooding and cave ins closed it for a period of time. the first years of the 1800's was it richest producing times. Gold bars for shipping were produced the size of 4ounze to 7 ounce was a way of keeping the shipping item into easy manageable size goods. The 4 bars above are what you can find in some shipwreck treasures but only 8 to 9 ct as Mt Morgan mine had not perfected use of its smelters and this can problem was at the beginning of the process as