I will search the NT for direction and any guidance on a liturgy. The Didache is probably the closest given the time frame. However that document is very basic which is evident of the PCC.
The New Testament does not prescribe a liturgy. That three of the Gospels make the last supper a part of the Passion of Christ, and the ritual that Jesus mandates, suggests that it should be part of that liturgy, along with prayers and Scripture and preaching.