Is This A Real Maria Theresa Thaler? Help!

@rick2020, there have been many very good CCF threads on this subject in the past. If you use the search box with the keywords MARIA THERESA, you will be able to go through them and learn a bunch, but here is a link to one of the best IMO:

http://goccf.com/t/132629

Also, consider checking out this website, which is wholly devoted to these pieces:

http://www.theresia.name/en/svariants.html

I would have to sadly say, no, it is not genuine. There appears to be a "wire rim" in places, there appears to have several large Cuds on the obverse around "SIA D G" and there is much missing detail, particularly on features near the rim (the top of the crown on the reverse, and the lettering around AVST. The details of the areas filled with "dots" e.g. the haloes around the eagles, are also wrong.

...I wasn't aware fake MTTs were a thing at all. Fake counterstamps on real MTTs, yes, outright fake MTTs? Way too common.

The missing top of the crown appears to be due to am overly strong die clash; you might note that the line exactly follows Maria's head on the other side. I suspect that some of your other "problems" also have to do with the same clash.

I do see the Cuds; why is that pointing toward the coin not being geniune? I'd have expected the other way around (i.e. that a geniune coin is more likely to have Cuds); but maybe it's a special MTT thing.