I suspect that the door control unit (the Green unit) which is located just above the fuses in the passenger footwell maybe fault as this appears to be warm which may account for the 180mA drain which drains the battery. When fuses F43 & F44 are removed the battery drain drops to virtually zero. The door locking function / windows operation all work perfectly. What I do not know is what else uses power via the F43 & F44 since I do not have a decent wiring diagram for the car.
What I would like is to compare to another Maserati before seeking a new replacement unit for Eurospares UK, unless you think the issue is else where? I could send a private message with my mobile contact details.
I'm going to suggest taking your car to see Vic at Scuderia Cavallino at 167 Parramatta Road Auburn.
They have the factory diagnostic computer and an auto electrician in house and don't charge the earth in dollars.
They have solved quirky problems I've had and have the low down on how to set up the clutch properly for long life.
Others on this forum and from the Maserati Club in Sydney can recommend them.