I have 2 used front tyres, Yokohama Advan Neova 175/55 R16s. I don't have a depth gauge, but I'd say they are easily 3-4mm.
I have pictures and can send them if requested.
Just trying to get rid of them and hoping someone can use them, so would be happy to swap them for a nice bottle of red or half a dozen bottles of a decent beer
Pick up from Gargunnock, Stirling, or nearby.
Colin