Again, many thanks for the comments everyone it certainly is a nice nugget and well worth the effort to dig it out, we both dug several other ridiculously deep holes only to unearth bits of steel/iron that the old timers had discarded 150 odd years ago. The GPZ7000 with the new 19" coil is a brute of a combination to detect with but man does it punch deep, used on selected ground it will be a winner.
Cheers, SinHof.
PS; Sandta, after the great star to the trip we managed another 15.7 grams between the two of us, all small bits, 1.2 grams being the biggest.