The location of the serial number will help date your Legnano. From my experience with Legnanos the 1968 and earlier frames had the serial number stamped at the top of the seat tube. My 1969-70 Legnano had the serial number beneath the bottom bracket. It also had the decal headbadge.

Your Legnano will be a bit more difficult to date since it has been repainted and had components changed. Does it have the threaded boss brazed behind the seat lug to support the center pull brake hangar?

We can see that the seatpost binder bolt is forward of the seat tube which makes it no later than an early 70's model as the seat post binder bolt was moved behind the post in the 70's. I'm disregarding the paint and decal scheme for this post as it could have been 'modernized'. Get back to us with the serial number and location and we'll move forward. Oh, that's a nice looking frame, repaint looks good. More pics, please.