Vintage Alfas also had Marelli electrics. The model year of my Alfa had Lucas electrics-positive earth- for the normal models while the Veloce models had Marrelli electrics. I had no troubles with the Marelli stuff, but the PO had swapped in a Lucas starter that caused no end of grief, including ruined ring gears. I finally bought the drive train from an a wreck just to get the Bosch starter. It was cheaper than buying the starter from the dealer.
The oil leaks were intentional- to keep the cheap steel from rusting.