EWTN Catholic Q&A
non-first time conclave cardinal electors
Question from vp on 04-16-2005:

who are the three cardinals who were cardinal electors in the previous conclave? were they also present in pope john paul i's conclave other than pope jaohn paul the great's? thanks!

Answer by Colin B. Donovan, STL on 04-17-2005:

Cardinals Joseph Ratzinger, William Baum and Jaime Sin were created cardinals by Pope Paul VI and were present at both conclaves of 1978. Cardinal Sin is too ill to attend this conclave, however.