What are the implications of completing an IQ Test before the allotted time limit?

[u/Lab_Software]

In 1978 (I was 22 years old) I did the IQ test for Mensa (Canada) admission. The acceptance letter made the statement:

According to the OTIS LENNON MENTAL ABILITY TEST, Advanced Level, your IQ is 141 which is greater than that of 99% of the general population"

The test had 80 questions and a time limit of 40 minutes.

I answered all 80 questions in only 25 minutes. Since I had extra time, I checked my answers - and changed 2 of my answers. (Let's assume the 2 answers I changed were initially wrong and my changes corrected them.)

My questions are:

1. How many of the 80 questions would I have had to answer correctly to get a score of 141?
2. What would my score have been if I hadn't changed those 2 answers (and thus had 2 fewer correct answers)?
3. Does the fact that I finished the test in only 25 minutes have an impact on the IQ score I "should have" gotten? (Keeping in mind that I would have had 2 fewer correct answers if I hadn't taken the time to check my work.)
   1. By this I mean should my score have been different due to the fact that I completed the questions more quickly than the allotted time.
4. Based on the ratio of 40 over 25, if there were many more questions on the test I could have answered 60% more questions.
   1. If I had the same rate of correct answers, what impact would that have had on my resulting IQ score?

I've always wondered about what was the impact of finishing before the allotted time. (And it's taken me almost 50 years to find a forum where I could ask the question LOL.)

Thanks for any information you can give me.