Communications methods and apparatus for preserving STIR/SHAKEN original attestation/signature information for diverted Session Initiation Protocol (SIP) messages and/or calls. An exemplary method embodiment includes the steps of: receiving, at a first Session Border Controller (SBC), a diverted Session Initiation Protocol (SIP) INVITE message corresponding to a first call, the diverted SIP INVITE message not including an Identity header; obtaining an original Identity header or information from the original Identity header corresponding to the first call using one or more of the following: information included in the diverted SIP INVITE message, information included in a Session Description Protocol message included in the diverted SIP INVITE message, an SBC trunk group, or a source Internet Protocol (IP) address transport protocol port of an IP packet carrying the diverted SIP Invite message; and generating an Identity header based on the original Identity header or information from the original identity header.