The ones in question have been made by Bruce Harper of Thames. Sadly they are so good, that they are often stolen or damaged!
Prospectors were a hardy breed, always hopeful that the 'big find' was in the next spot they mined.
So as you wander around the town keep a look-out for the other sculptures made by Bruce. Out by the "Welcome sign' to Thames, at the end of Albert Street, by the Croquet club, and sitting on the remains of the old Burke Street wharf.