Well then, the newspaper headline settles it. Vito was shot on Dec. 21st. Now, we don't know how much time transpired between that and the Sollozzo meeting. Since Mike's face looked pretty good at the meeting, that either reflects a movie production decision or that Mike's face had enough lapsed time to heal pretty good. I believe the former. Still it's probable that either side wanted too much time to elapse before attempting a peace or another try at Vito.