Ladies Jacket Seam Allowance

Hi - I just completed the draft of the jacket just following the video with the same sizes. I want to do a couple more practice drafts using a couple of my friends measuements before I actually cut any fabric. When I measure them if say they have a 39" bust then maybe a 41" seat and waist of 36" would I add seam allowance of 3/4" to all those measurements to give me 3/8" on each seam. So now the bust becomes 39 3/4", the seat is 41 3/4 etc? And do the same on the sleeve measurements?

I also don't remember seeing anything about wearing ease being added to the measurements - do I need to also allow for that and if so what number would that be?

If i do have to add to the measurement can i assume this is also the case for the waistcoat which I have also done the pattern for but would like to try out on my sons who are differents sizes to the video series?

Thanks