There's no way to tell what score you would have gotten, unfortunately. The algorithm is too complex - your performance would depend on what would have happened on whatever new questions you did get.
If you answered all of them correctly, chances are you artificially inflated your score because you probably wouldn't have gotten every last one correct if they'd been totally new.
Further, you said you answered 7 to 8 questions almost immediately, which would have saved you around 15 minutes, but you finished only 8 minutes early - so you gave yourself extra time on some other problems - and you normally wouldn't get that extra time. That could have artificially inflated your performance elsewhere.
All of this almost certainly inflated your score, probably by a decent amount - but it's impossible for me to tell (or even ballpark) how much.
To get a better sense of your current level, you can try taking a GMATPrep or other test where you won't see questions you've seen before.
Also, you're either taking the tests too closely together or you're taking them too many times (to recognize so many questions). Read this:
https://www.manhattangmat.com/blog/inde ... many-cats/Next, if you want specific advice about what to study, we need detailed data on your strengths and weaknesses on the verbal section - and that data needs to be relatively "untainted" (so, not from this last test where you knew a bunch of the questions already).
This is how you can analyze your MGMAT tests:
http://www.manhattangmat.com/blog/index ... ice-tests/(Again, though, if the starting data is "tainted," then the analysis won't be as useful.)
Have you read these yet?
https://www.manhattangmat.com/blog/inde ... lly-tests/http://www.manhattangmat.com/blog/index ... -the-gmat/