Pranams,
http://http://www.amazon.com/Ancient.../dp/B0006EYR9K
Quote

The original Bhagavad-Gita had 745 verses but the vulgate text has only 700 verses. The author discusses the various Gita manuscripts and sheds some light on the source of these extra verses. The summary of this book is as follows: The existence of 745 verses is found in Mahabharata (Bhisma Parva), IV, chapter 43, verse 4. One of the Kashmiri versions found by Indologist Otto Schrader in 1930 had 745 verses with few partial hymns (Sloka-padas); Gita commentator Abhinava Gupta used this version in his interpretation of Gita (Gita-bhasya). There are about 150 commentators of Gita over the past two millennia and most of them are after Adi Shankara and the first three who precedes Adi Shankara, interpreted 745 verses: The earlier Gita had no chapter headings but they were later interpolations. Commentators like Abhinava Gupta, Ramakanta, Bhaskara and Vedanta Deshika all substantiate the existence 45 extra verses. There are two Persian translations that also have 745 verses.

Most modern scholars use Adi Shankara's Gita-bhasya as the standard because it is the vulgate text with 700 verses. But the extra 45 verses are similar to any other Gita verses and run parallel to Vedic and Upanishadic literature.

The author gives a rare piece of evidence for Mahabharata in the form of a copper plate issued in the 89 year of kaliyuga in the cyclic year Plavanga by king Janamejaya, the great grand son of Pandavas. This is known to have been issued at the time of king's sarpa-yaga (snake sacrifice). At the end of the book you may find the full 745 verses of the original in Sanskrit (no transliteration given). The book is an interesting addition to other books in literature that discusses the original Bhagavad-Gita.

Unquote

What exactly are the missing verses, any further information would be appreciated.