For US MMEL, all are available for download at the FAA website. Keep in mind that the operator is entitled to generate an MEL quite different from the MMEL with the proviso that relevant approval processes are met.
Yes John, this is very true.
All regulatory bodies I worked with insisted to have a sentence in the approved MEL similar to:"This MEL is based on the manufacturers MMEL and will in no case be less restrictive than the MMEL."
As said, there are companies which simply remove a page in the MEL after the same was approved..... How are you going to find out if there is no MMEL on board?
And how will you ever discover this if the item is not installed also it was a mandatory retrofit years ago?
Yes, items installed and not mentioned in the MEL are essential and if faulty an engineering action is required before flight.