Hello and welcome to the group
We have several Italian members who i'm sure will comment when they read this
There is a description of the Italian side markers in the technical manual, you'll need to register as a full member to access the manual, which is well worth the small cost for an owner. Use the Techncial Manual button above left
See
https://www.sl113.org/wiki/Electrical/SidemarkerThe Italian side markers look really neat, not at all obtrusive and easy enough to fit, it appears they're only needed on the front wings, but others may know more. if you use the search button, again top left, search for Italian, and it will throw up lots of posts and pictures of Italian spec cars
Under "tail lights" in the manual there's also details of the Italian rear lights
Changing equipment to meet local rules and regs is quite common, nothing really to worry about
Let us know how you get on