rust "tendril" AKA a "spiderweb of rust" under the paint on the outer blade, probably some wheel rub caused the chip on the inner blade, Id not be too alarmed by either.
Given the 27.2 seatpost you are correct to conclude probably SL tubing (rifled steerer would further confirm this) and a "Mockba 80" is as good a guess as any for the correct model.
Yes, the Pelizzoli signature decal was used for MANY years on MANY models long after Giovanni sold the name off to the Bonati or Billato (you tell us!) new owners.