Here's what I did. After talking to Koni, looking around at other forums, and input here, I believe this to be correct.
Working from top to bottom of installed shock:
Koni flat metal washer
shock tower sheet metal
OEM Alfa metal washer (inserted in old dust boot to keep boot in place)
Koni nylon split washer (below piston weld, against top of shock body)
OEM Alfa dust boot over the top of it all and slipped over the shock body at the bottom of the boot.
Some thought that nylon washer would not stop the shock from bottoming out. That may be the case, but it does look designed to slip between the weld and the top of the shock body while not expanding when compressed (i.e. when the shock bottoms out). Whether it actually achieves that end, I will leave to engineers to figure out. ;-)
HTH. Thanks for the input everyone.
Current: 85 GTV6, 69 Duetto, 17 Giulia, 74 GTV
Past: 65 Giulia Sprint GT, 77 Alfetta, 79 Alfetta, 87 Milano Gold, 74 GTV (Euro)
Last edited by crackie; 01-19-2018 at 10:08 AM.