That's my experience with European cars. Every one I've bought second hand has had stuff I've had to rectify, damage inflicted by lazy/uncaring/ignorant/incompetent "mechanics". Euro stuff is generally easy to work on and perfectly logical - if you know what you're looking at....
I'm thinking the second oil leak on the Alfa might have something to do with first installation of the transmission part. But who knows. It is what I bought a new one - less chance of it being fucked with. That didn't last long...