Thanks. I have emailed them to check. We now have no chain (or anchors or warps) - all our ground tackle is in the Indian Ocean part of Davey Jones' locker - so we have an opportunity to rethink. We're considering using high tensile chain of reduced size in a mixed rode. It appears from Maggi's web site that they are marketing a properly hot dip galvanised G70 chain, (but that part of the site is in Italian only).
I have contacted Island Chain - very helpful but they no longer supply Italian chain, suggesting it's next to Chinese on the quality scale!