Hello George,
just a little note or idea from me.
I have also had this situation many times and some can solve, others not.
The fact that the person who made the entry did not know the bride's last name and the father's name actually testifies that she was not from the parish. Even if there was a more distant type of relationship here, he did not know the names.
So there is a high probability that she came from a neighboring parish. Since it was common in Germany (also Austria) that marriages took place in the village of the bride, but this did not happen (assuming that she came from another parish), it could be possible that her father was already deceased. In these cases, however, a parish register entry was often made in the bride's parish, indicating where the marriage actually took place. Engagement entries, proclamations, etc. were also common in some cases, and they were then noted in both church books (some in engagement books, some between marriage entries). These are usually found 2-6 weeks before the wedding.
You might have luck if you search the surrounding parishes.
Good luck