Found this on a QSL mgr list-Depends when and who you worked it looks like..
I have not had much luck going to LU QSL mgrs thru the years.



LU1ZA QSL via LU4AA (Nov.1996) (see also LU4AA *)
LU1ZA QSL via LU6EF (for 1989) (see also LU6EF *)
LU1ZA Serv. Auxil. De Radioafic. De la Armada, Av. del Libertador
8209, Capital Federal, CC 1429, Argentin
LU1ZA QSL via LU4AA (for 1995) (see also LU4AA *)
LU1ZA QSL via LU2CN (for 2001-2002)
LU1ZA QSL via LU4DXU (for QSO with Op. Claudio )

73
Joe W7KQU