As for coin #3, my opinion would be "genuine, but poorly re-toned". All ancient coins (except maybe the gold ones) require cleaning of some form after they've been dug up. The cleaning process usually strips any tarnish from silver coins. Now, you can wait decades for the coin to re-tarnish naturally, or you can try to hurry things along - tarnish can be re-applied using sulfur-based patent formulas like Dellers Darkener, but as with any art, you can do a good job, or you can do a poor job. This coin looks like a poor job.
I haven't been able to find a quote and reply button yet so have added [quote parts above, hopefully it works. Is that the right procedure?
Anyhow I wanted to say thanks for your replies Sap, they are greatly appreciated.