Hello again!
Thats glad to hear that you are great and that you enjoy maths and physics (the 2 objectively best subjects lol)!
its a fun wee challenge not going to lie, I had to search around the internet for some notes - im sure your familiar with DLB maths? he also does mechanics past papers - he might be the only - they are quite helpful videos to understand how everything works
for some of the centripetal banked motion I watched eddie woo - another great mathmetician - I just typed up "eddie woo centripetal force" I would watch as many videos on the individual units as possible, I think the "Organic Chemistry Tutor" has some physics/mechancy kind of videos as well
for websites
for this one i would recommend finnishing the homeworks before going into the exam
https://www.national5maths.co.uk/free-ah-mechanics/This one is where I found more questions - not past papers but more standered notes for them + if you look around this website you can find an unofficial formula sheet where you will have to memorize all of the formulas within it - you may not be aware but you have to memorize alot of the higher/ah physics formula for motion ie F=mv^2/r rotational motion etc
now - for the new topics comming back into the course centre of mass and moments I dont know where to look for good notes specifically but im sure you can find
books for A level maths - mechanics that teach more than what you require if your interested in getting physical books - I dont remember seeing any books for specifically AH mechanics but you can buy some from the A level syllabus under mechanics and further mechanics (A or AS level i cannot remmebr but youll notice it when you get to going through the topics)
but you might have to ask people about these books and get information that will help you more for a proper book to go through
Also one last thing when attempting the past papers the pre 2015 papers are alot harder compared to todays standared.
if you have any more questions go ahead and ask them!
well good luck!