I believe I have devised who all 7 members of marco pollo's crew are and some info about their map pieces:

Marco Pollo: His map piece was taken by the Armada in Valencia
Christopher Clark: His map piece was stolen by Captain Blood but recovered by you in Cool Ranch
Egg Foo Yung: His map piece was stolen by General Tso and given to Rooke in Mooshu
Catbeard: He lost his map piece to Captain Gunn and was later recovered by you from Fin
Argos: His map piece was taken by Ulyssyes (probably spelled it wrong) and later recovered by you in Aquila
Erica the Red?: Currently unknown, other than the fact that Avery montioned her in the picture.
Parent: One of your parents apparently had one of the map pieces, but the location is currently unknown.