It looks like my first introduction to Thriller (the next ep on MeTV) will feature Karloff:
THE PREDICTION
Original airdate: 11/22/60
An engaged couple (Audrey Dalton, Alex Davion) ignores a psychic's (Boris Karloff) warning of death.
Also, if the listings on my DVR are correct, it looks like MeTV is playing the eps in their original order, including having the Sunday at 10pm ET weekend ep following along after the eps from Tuesday-Saturday at 3am ET, meaning the Saturday at 3 ep originally ran 11/29/60, and the Sunday at 10 ep originally ran 12/06/60, and then the Tuesday at 3 ep originally ran 12/13/60.
According to tv.com, the ep with Elizabeth Montgomery originally ran 10/30/61, so there's a while before that one might show up.