There were no introduction/preaching schedules for the sermons on Genesis.
1. Genesis 12-13 Abraham: the Tent and the Altar (Jeremy Jackson) 9-20-81
2. Genesis 14 Abraham's Character (Jim Pitcher) 9-27-81
3. Genesis 15 Justification by Faith and Covenant of Grace (Al Gurley) 10-4-81
4. Genesis 16 The Barrenness of Human Schemes (Jeremy Jackson) 10-11-81
5. Genesis 17 Abraham's Obedience (Bill Finch) 10-18-81
6. Genesis 18 Reformation Sunday Pulpit Exchange (Gordon Bell) 10-25-81
7. Genesis 19 Sodom: A Parable of Judgement (Jeremy Jackson) 11-1-81
8. Genesis 20 God's Determining Grace (Jeremy Jackson) 11-8-81
9. Genesis 21 Promised Isaac and Ramification (Al Gurley) 11-15-81
10. Genesis 22 The Sacrifice of Isaac and God's Provision (Bill Finch) 11-22-81 [quality improves slightly after 15sec, then drastically about halfway through; ends with Bill Finch song "A Sacrificed Lamb"]
11. Genesis 23 The Price of a Vision (Jeremy Jackson) 11-29-81
12. Genesis 24 Isaac and Rebekah -- Type of Christ and His Church (Al Gurley) 12-6-81
13. Genesis 25 The Patriarchal Succession (Jeremy Jackson) 12-13-81
14. Genesis 26 Faith and Flesh: Patriarchal Alternatives (Jeremy Jackson) 12-20-81
For the missing sermon, I particularly recommend the Gospel Coalitions sermon collection, which generally has high standards for what it includes. I would personally recommend any sermons by Iain Duguid, Alistair Begg, or Ligon Dugan, and all three of them have sermons there on chapter 14.
Jeremy Jackson also preached a sermon on Genesis 12 entitled "A New Beginning" on New Years Eve 1989. See the topical sermons here.
Bill Merry preached a sermon on Genesis 12:1-3 entitled "The Call to Mission" in 1996. See the topicals here.
Gerry Malkus preached a Reformation Sunday sermon on Genesis 15:1-6 in 2008. See the topicals here.
For more sermons, see here.