What was wrong with the original header here?  It sure looks good to me.
Does the parser not handle commas in comments?  They are definitely
allowed, according to RFC822.
 
Comments:     <Parser> E: Mail origin cannot be determined.
Comments:     <Parser> E: Original tag was FROM: Roger Watt (NetNorth Rep,
              UnivWaterloo) <ROGERWAT@WATDCS>
Comments:     Warning -- original Sender: tag was FUTURE-L@BITNIC
From:         Undetermined origin c/o Postmaster <POSTMASTER@BITNIC>
 
Richard A. Schafer
Manager of Systems Support