You are right ,there is some similarities between SIAT 222 /SIPA S-251 Antilope.This was the early sixties " mode " for all-metal low wing four seater.BUT in fact the SIAT 222 is an original design.
About the SIPA , it was born in Italy , it was an aircraft designed (and
some parts already built ) by PROCAER .(wo built the FRATI's Picchio )
Forgive me I am somewhat confused. You say the silhouette posted at Post # 4398 is the SIAT 222 yet every photograph I have seen of the SIAT 222 shows a "squarish" Vertical Fin and rudder yet the silhoutte shows a swept vertical fin and rudder which conforms to the SIPA S-251 Antilope. The SIAT-222 was the precurser of the SIAT-223 Flamingo. The SIAT 223 certainly does not have a swept fin and rudder.
Photos: CASA / SIAT (MBB) 223-A1 Flamingo Aircraft Pictures | Airliners.net