The 25 marking in the shell is the frame size in inches, measuring c-t-t. Rizzato did this on their products at this time, at least the ones for export to the English speaking world.

Cesare changed from using an Agrati lugest to the Prugnat in ~1968. Frame's seat lug looks to be an Agrati pattern. AFAIK Prugnat did not offer Malaguti type seat lugs. Shell and bridges are likely Agrati products as well.

Here is an Atala models crosstable from 1973. Looks like your frame would either be a model #101 or a model #109:

http://www.classicrendezvous.com/Ita...ala_advert.htm (sofware would not allow image to display)

Tubeset will be A.L. Colombo SP.

Atala and Lygie brand bicycles tended to be the same in the metal, differing only in finish and transfers. Also a possibility machine may have been sold as some third marque as the company did a bit of contract building as well...

The letter "A" in the serial does not necessarily mean the machine is an Atala. Here is a chrome 1973 Lygie serial:



This 1972 Lygie appears identical in the metal to your frame:

https://utahrandonneur.wordpress.com...-carousel-4997

As does this 1970 Lygie bare frame:

https://utahrandonneur.wordpress.com...-carousel-4617

With a big thank you to our Lonnie or his Lygie site!

https://utahrandonneur.wordpress.com/the-lygie-barn/