After a little more study, I will go out on a limb and say I am 99% sure this is a
cast copy... casting bubbles, ( which seem to adhere more to the laws of gasses in fluids than they do corrosion in soil..),
soapy surfaces, it looks distinctly wrong...
sorry.
( of course I could be way off the mark, and if so I will eat my words, but unfortunately I doubt I will have to.)
With best wishes,
Lee.