Very nice car Snoopy.Regards the sump plug,the new one you have there is the correct one.
The early mk6 was fitted with the old type and was found to cause leeks on some cars,so was
Changed to the smaller one with the copper washer,the washer on the other one was not soft enough.
My wife has a mk6 1.4tsi and it has the older type,because the sump is made of a different mix of alloy.
That's the info supplied from my dealer parts department anyway.