Well, no doubt there were lots of cahnges as the PRINCIPE had to be almost completely redesigned, as Gibbs&Cox documentation on the SCS was sketchy. Looks like the SCS design was never fully completed due to the lack of interest from the USN and the ultimate cancellation of the project.
This also explains the long building time. Even after the hull was launched major design work was being carried out. For example, the CIC was completely redesigned between 1982 (launching date) and 1988 (service entry). Other items such defensive armament placement was also decided after the hull was launched, while Meroka itself was still not frozen at that time!