I'm stoked!! thank you all for your comments. I wasn't searching for relics or coins, I was poking around looking for gold. Suddenly the sdc began screaming its head off, at first I thought it was a lump of rusty iron, but, they say to investigate all signals and about 25cm down I got this odd looking coin. I asked a fellow prospector nearbye and he said it was a fourpence. Never heard of one, heard of thrupence. He also told me that it was an old pommy coin and that they also made fivepence as well. I'll definitely be keeping it. You can buy dozens on e-bay, cheapest being around $10, but it's not the same. This could have bought a meal for the poor miner.
The place is at Talbot, off Possum gully rd. Someone else from our group pulled a 2 gram nugget over 40 cm down with a GPZ7000. My 2 pickers together would be about 1/2 gram. I doubt that my sdc would have picked the 2 grammer at that depth.