I did the search and found it very interesting. And I found this by Swampbob
"One of the differences noted above is the shape of the you in AUST. There are two letter shapes you and V. This one has U.
I just want to make the you vs V distinction clear - all MTT's made during Maria's lifetime have the round U. All copies with V are restrikes made after her death, but there is a small group of varieties that use the Round you and which were struck shortly AFTER her death (up to 1805) - all are scarce and in general are on a par with originals in value. So if you have a MTT with the round you it has to be one of the following Hafner types: (originals in red)."
As a result of these comments I now know that mine is a restrike because mine has the V rather than the you in AUST