Cantagalli?

Picked these up recently out of sheer curiosity - they're damaged (chipped, hairline cracks etc), but I'd never seen a rooster backstamp before! - searching the web for answers brought me to the experts here - very similar to Cantagalli or Galvani marks identified on other threads on this website.
I think they're shallow soup bowls - probably part of a larger dinnerware set, about 8in (20cm) diameter, exposing a pale reddish material (terracotta?) beneath where the white glaze has been chipped/rubbed. No backstamps or impressed marks seen, other than the hand-painted roosters and numbers (11 and 17).
Would welcome an opinion, and if possible identification of the pattern and possible date.

 

WELCOME Rummager !!! ... Joy.

 

Note that the plates are not marked with a country of origin. That would indicate that they were made before the imposition of the McKinley Tariff Act (1890). This is a bit of a problem. The design on the plates are not correct for the period. I do not believe that your plates were made in the Cantagalli factory.