Found this morning just about made out XVI in the " field photo" after careful work with a toothpick and even more carefully with a dentist pick, found to be a Lou XVI 2 Sols unfortunately the detail does not include the date. On further research he was the last king of France reigned from 1774-1792 and was married to Marie Antoinette.
Found with the Manticore, stock coil, All terrain Low conductors setting, Sensitivity 22, Reactivity 6, GB set at 0.

Manticore, XP Deus 2, Minelab Pro-Find 25 pro pointer, Nokta pro pointer.