Thought the significant engine change was during the Duoselect era?
The early cars have red cam covers, indicating dry-sump engine. The blue heads are wet sump (info from Roberto Grimaldi - during my PPI)
Was tehre yet another change of engine version?
Maserati UK emailed me and said my chassis number corresponds to a Quattroporte GTS
Yay, I am awaiting a detailed copy of the spec.
I'm surprised that the selling dealer didn't tell you what it was...