Mr P, I can't agree that this list is a "bare minimum". (3) assumes some knowledge of statistics and (6) is far too advanced and theoretical. Measure theory? You can't be serious. That's graduate level maths which very few people would be capable of understanding, even if it were relevant. The early chapters of (7) are quite nice but again too theoretical.
I doubt very much whether Real has read any of these books. And he's the first to admit that you don't need advanced maths to be an AP.
Also, since (2) isn't available (and I don't think Real would be too happy if you uploaded your copy) it seems that wannabe AP's are out of luck; they'll just have to make do with systems.
If your knowledge of stats and probability is zero, I would recommend some or all of the following books, in order of difficulty:
1. Statistics without Tears : An introduction for nonmathematicians - Rowntree
2. Probability without Tears - Rowntree
3. Probabilty for the Enthusiastic Beginner - Morin
4. Statistics: A Bayesian Perspective - Berry
5. Practical Statistics Simply Explained - Langley
6. Multivariate Statistical Analysis: A conceptual Introduction - Kachigan
7. Analyzing Multivariate Data - Green, Lattin, Carroll