When working on an Italian car you will find that there are seals and o-rings everywhere. Some are obvious and others are a little harder to find. To find them all it is important to get a parts book and check EVERY assembly piece by piece to make sure you have not missed anything.
Case in point is an oil seal that is in the speedometer drive unit on the gearbox. Previous 'experts' had just tried using more and more silicone to try and stop a leak without knowing that there is a dedicated oil seal deep in the assembly. Sure enough disassembly revealed a seal that was hard as a rock and crumbled upon touching it.
We found such mechanical sins all over the place as previous maintenance and re-builds only replaced the most obvious seals. We are adamant of replacing every millimeter of rubber on the car so it is essential to use the parts book as your guide.