This is an absolutely fantastic site I came across by accident today. It looks as if it has thousands of pencil drawings of Italian ships, including several hundred of the Italian navy including auxiliaries. The drawings seem to be based on photos, as you can see below.
Unfortunately in Italian only, but it should be easy enough to manoeuvre for ship lovers. Below a drawing from the site and the corresponding photo of Sagittarius, from the Italian Wikipedia.
Sagittarius was a 600 ton escort of the Spica-class, sub-class Perseo. Sagittarius survived the war and soldiered on until 1964, before being stricken from the naval list.