Dear Matt,
I do not know about the Imprimatur, but do know the the entire Light for Life series is now considered the ultimate Eastern Catholic Cathechism series. It was produced under the supervision of the Eastern Catholic bishops in the United States.
Here is a link if you wish further information.
http://www.ecdd.org/ Enjoy. Your book is good reading.
Here is a list of the bishops:
Archbishop Basil Schott, Metropolitan of Pittsburgh (Byzantine Ruthenian)
Archbishop Stefan Soroka, Metropolitan of Philadelphia (Byzantine Ukrainian)
Archbishop Cyril S. Bustros, Bishop of Newton (Byzantine Melkite)
Bishop Jacob Angadiath, Bishop of St. Thomas in Chicago (Syro-Malabar)
Bishop Manuel Batakian, Bishop of the Armenian Exarchate (Armenian)
Bishop John Michael Botean, Bishop of St. George in Canton (Byzantine Romanian)
Bishop Ibrahim Ibrahim, Bishop of St. Thomas the Apostle (Chaldean)
Bishop Sarhad Jammo Bishop of St. Peter the Apostle (Chaldean)
Bishop John Kudrick, Bishop of Parma (Byzantine Ruthenian)
Bishop Basil Losten Bishop of Stamford (Byzantine Ukrainian)
Bishop Gregory Mansour, Bishop of St. Maron in Brooklyn (Maronite)
Bishop Robert Moskal, Bishop of St. Josaphat in Parma (Byzantine Ukrainian)
Bishop Andrew Pataki, Bishop of Passaic (Byzantine Ruthenian)
Bishop Nicholas Samra, Titular Bishop of Gerasa (Byzantine Melkite)
Bishop Richard Seminack, Bishop of St. Nicholas in Chicago (Byzantine Ukrainian)
Bishop Robert Shaheen, Bishop of Our Lady of Lebanon (Maronite)
Bishop William Skurla, Bishop of Van Nuys (Byzantine Ruthenian)
Bishop Joseph Younan ,Bishop of Our Lady of Deliverance (Syriac)
Michael