*marks on hooves: ponies made in Italy have a typical ITALY mark carved on their hooves. Note it is never printed, but carved. I am unaware of any pony made in Italy without the country mark on the hooves. NOTE factory marks can be either on 2 or 4 hooves in early ponies, and different issues of the same pony can come with marks on 2 hooves or on 4. They can or can not have a PAT PEND mark.
*eyes: it is a common belief that Italian ponies have dark blue eyes. This is only partially true. IT ponies have blue eyes indeed, no matter what the Hong Kong counterpart's eye colour was, but this does not mean they only feature just one eye colour. There are at least 3 different shades of blue that were regularly used to paint IT ponies eyes coming in the different issues: dark blue (the most common), turquoise (the eye colour of the very first issue, I believe), and light blue, extremely similar to Macau ponies eyes (certain later issues). This different colours are NOT due to fading.
*symbol: the symbol of IT ponies rarely looks the same as the HK counterpart: colour is usually darker, shape and size are different. NOTE symbol shape, colour and design do change a lot among the different IT issues of a certian pony. Also, typically all IT ponies whose American counterpart made in Hong Kong has a glittery symbol, have metallic, painted-on symbols.
*forelock: like most non-US ponies, IT ponies too do NOT have a forelock.
*mold/pose: different issues of a certain IT pony come in different mold/pose. This difference can be slightly, barely noticeable (like different 82 molds) or a completely different pose (like the walking pose as a later alternate pose for certain early unicorns). Among the different 82 ("collector") pony molds we can easily recognize the "feet-apart" mold, or "hunckback", the "short-legged", etc..
-unlike HK ponies, white IT ponies rarely yellow
-on the other hand, pink IT ponies tend to fade - a mint pink IT is rare as gold dust. To check whether a pony colour is due to fading it is a good idea to check it inside.
-unlike HK ponies, IT pink hair *usually* does not fade. Usually. but it happens, especially in later issues.
*quality: ponies made in Italy are overall NOT as well manufactured as ponies made in Hong Kong or France, but better than Greek or Spanish ponies.