The old exams you downloaded are the older, longer version. The ones you purchase online from AAMC are the newer version which have less questions/less time.
However, all of the questions on the new CBT version will also be on the older "R" versions. The new ones were only created by removing some of the questions from the longer versions. I believe the old ones only go up to test 7, so 8-11 will be fresh.
I used both to study. I started taking the longer versions to build stamina, then eventually switched to the new CBT versions. But I always went back and did the extra passages on the R version that did not make the cut onto the CBT.
Hope that helps. It can be confusing until you actually look at both sets of exams. Good luck.