Some local Brit might have had the coins, but I can’t imagine anyone but the Romans would be putting garum/fish sauce on their food-the modern version made in the Far East is bad enough-the smell alone could make a hungry bear puke...
We keep fish sauce around the house. We have some great Asian recipes that are just not the same without it. I bottle goes a long way though since the flavor and aroma can be overpowering if not used in small does.