If you got them right even though you think you might not have if they had been new, then yes, you might have inflated your score.
How much time did you spend on them? Did you take the full 2 minutes for each one or did you answer more quickly than you otherwise would have? If you answered more quickly, then you also gave yourself an artificial time advantage, which would help you on other questions. So that could inflate your score even more.
(For future reference: if you are taking any CAT and see a question you recognize, make yourself stay on the problem for the average length of time for that question type. Do the problem again. Then ask yourself, completely honestly, whether you would get this right if it were new. Answer accordingly - get it wrong on purpose unless you are confident you would get it right as a new question.)
And what do I do to get SC up to 90-95% accuracy?
Wrong question. You need to be able to get harder questions right to lift your score - but you're still going to get even harder questions wrong!
So it really is about continuing to practice / analyze what we discussed last time: the most tempting wrong answers vs. the right ones.
How many real tests have you taken in the last 12 months? (You're limited to 5 real tests per 12-month period.) As long as you aren't at or close to the limit, you might as well take advantage of the pilot. It only costs you $250 and half a day of your life, and you can always cancel the test if something disastrous happens.
If, though, this would be test 4 or 5 in that period, then you have a harder decision to make. When would you be allowed to re-take again (ie, when was your oldest test)? If you took it twice 11 months ago, then no problem; those 2 tests will fall off the list in another month. If, on the other hand, you took it 4 times in the past 3 months, then you'd have a significant delay before you could re-take again.