If you open her you'll see how the tail and mane were secured. Here you can see how an original Italy tail looks like: http://mlparena.com/index.php/topic,398994.msg1819791.html#msg1819791. I don't know what technique the factory in Italy used to secure the mane as I've never opened an Italy pony so far and the ponies I had re-haired came back to me re-glued, but I'm sure there are several people on here who can elaborate on this.
So many years of collecting and I didn't know about this fact
So...Somebody suggested to "squish" her butt and tell what I feel, so I did (Sorry, Trickles
) There's something hard where her tail goes into the body. It's about 1 cm long and if I press real hard (I had to use a clamp tool for some of the photos or it wouldn't show) the shape / outline is visible. I held her against a lamp to make it visible for everyone. I also took many more photos from different angles, also very clear closeups from all sides. She really looks genuine to me. No harm on the neck seam at all.
Here's one of the pics (more here on the bottom:
https://www.flickr.com/gp/105219357@N03/ypZReW