"A journey of a thousand mile begins with the first step".
I will try to answer your questions if I know. Anyway in the forum, there will be many people who are knowledgeable, so they will help too.
For your question, I think you would like to know what is the calibre used in the MM GT XL 2007 Chrono.
The movement on the MM GTXL Chrono (limited ref 168489-3001, 168489-5001 and non-limited ref 168459-3001) is a mechanical self-winding Valgrange A07.211.
Haha...life is moving very fast so, need an escape. So winding/adjusting a watch is always a pleasure 
Kong