Thanks for the information...
In fact one of the TRTO wants that I join one of their training within a few days. Their initial pre-requisites were valid CPL, class 1 medical and 500h on multi-crew aircrafts (jar 25). When I told them I had no jar 25 hours , they told me it wasn't important, it was just to avoid people with no experience at all, few times ago there were special type rating named "additional type rating" for people with more than 500h multicrew, but it doesn't exist anymore... So from what they said I can Join this training although I have not the official pre-requisites...
I checked the type rating examination form and it's true that they don't ask if it's a First type rating training or an additional one... They just ask a copy of MCC and Frozen ATPL if it's your First multi-crew type rating...
I'm really interesting by this TRTO as I would Start within a few days.
What do you think about it?