Plonker, that bit about advertising far and wide for specialist miners really rings a bell with me. My Sennetts (Sinnott) were in the Avoca copper mines directly prior to going to Whitwood, and it does seem that a number of families emigrated from Avoca about the same time. What is even more interesting is that it would also appear that a generation or so before, it was cornish miners going to Avoca! Given that the Sennett name is also really common in cornwall, I wouldn't be surprised to find that my Sennetts, far from being Irish through and through, were originally from cornwall!