Dave -
How long is an aptitude pass valid for? Might be worth checking. I can't honestly comment or advise otherwise, other than to say I had a similar experience going through OASC.
I initially applied for a University Cadetship and passed the aptitude tests although didn't quite make the grade for a Cadetship. I then went back a couple of years later for DE and was told I had to re-do all my aptitude tests; my concern was failing them second time round having passed them first time round. When I asked I was told not to worry, it was just a formality and they would consider my highest score obtained from either of my test sittings rather than just looking at my last set of scores. Fortunately I passed again, so not a worry, but nice to have that knowledge in the bank when you sit the tests.
Not sure if the same applies to FAA, but might be worth asking.