Steve,
There are some very good resources available for the 75 at "Craig's Place" at the link below.
Craig's Place, Alfa 75 Manuals and Information
Lots of scans of manaul sections.
Group 40 and 43 are electrical related.
Page 40-39 shows details of the 'Sensors and Senders'
The 'Low Oil switch is "L12" at the bottom centre of the page, fed by grey/red wires.
There are also many threads on the forum concerning flashing lights on the ARC.
One you should check out before you go to far is
http://www.alfabb.com/bb/forums/mila...ng-lights.html
Hope this helps and have a search throught the Milano/75 board.
Regards, Alan.