It is great to see some Abhidhamma enthusiast here.
If you are a beginner it is a good idea to read the summary of Abhidhamma by Mr. N.G.K. Mendis.http://www.accesstoinsight.org/lib/auth ... el322.html
I use Ven. Narada’s Manual of Abhidhamma.http://www.stefan.gr/buddhism/
In regard to your OP, please consider 52 mental factors are only a guide to understand your mental state in a given time.
When you meditate you can be aware whether you have anger, attachment, remorse etc.
It is like the spectrum of colours. We say there are seven colours. But it is a quite an arbitrary notions.
If you go to a paint shop you can see thousand of colour shades.
Colours are the visible lights. There is an invisible light spectrum as well.
The same way there are mental states only can be experienced by meditators.http://en.wikipedia.org/wiki/Rainbow