You might also find this book interesting. History of Metals In Colonial America, by James Mulholland, 1981.
This book concerns the colonies and does not address Spanish Florida. Still, very interesting.
You can view a substantial sample of the book free online. There is a lot of interest reading in that book. It covers iron, copper, silver, etc.
This book explains how silver coins were melted and made into other objects such as silverware. Those silver objects were marked and more easily identified if stolen. And if and when cash was needed the silver could be easily converted again.
You'll find a lot of interested facts about metals in the early days of the colonies.
Click above to read the free sample sections of that book.
When I had an injury C Man sent me an email telling me about a detector harness. He got one for his wife. If your arm gets tired when detecting, you might think about getting one.
Here is a YouTube video C Man sent me showing the harness in use.
I actually have one that came with a detector that I bought, but haven't tried it out yet.