Yes they are virtually unknown outside of Italy, i only came to learn about them and their history as i began to search for tuner parts, and saw a few with their name on it, and some talk about them. I then went down that rabbit hole, lots of interesting history especially between Giannini and Abarth. I was also a big fan of Davide Cironi's videos; with the help of captions. lol
I think Giannini has a missed opportunity here. They are still around and family owned. They have a site, but barely any info. They have a shop, but no actual parts to sell. Do they even offer the option for dealers to carry their parts? I realize that a large part of their "tuning" can only be done in house, but i personally see a potential market if they offered all the classic hop up goodies alot of us go on the hunt for (carbs, sumps, exhaust, heads, cylinder kits, etc). Abarth doesnt offically make any 500 parts any more, its just a brand and a badge now that its corporate owned. It would be nice to be able to buy genuine Giannini 500 modification parts. In Davide's video, it seemed like they were very busy back in the day doing just that. Bits and pcs that 500 owners could buy and slowly upgrade their car as funds permitted.
Maybe they see the market over saturated with other generic upgrade parts, and its not worth their time to re-enter?