Hi Jay, excuse me if my information is not exhaustive on the issue, I only began looking into it when I read your post.
I must admit that after reading Genesis 11:26 I would expect, as is somewhat indicative of Scripture, that this would imply that Abram, Nahor and Haran were born in and around the time when Terah was 70. So then yes, if Terah died at 205, and Abram was 75 when he left Haran, and that Abram left Haran after Terah's death (Acts), there would be actually a 60 year discrepancy between when Terah conceived Abrahm.
I have no conclusion outside of capitulating and stating that Terah had Abram at 130. I don't like this, because it makes the assertion that Terah was 70 years as entirely pointless, if there is no reference point. For if he lived till 205, then obviously there was a time when became 70, or 75, 87, 102 and so on. It's a superfluous point, verging on frivolous and silly. And, I can't recall where the Bible does this elsewhere, in the same manner that it was defined in the entirety of Genesis 11. The account of Noah, Abraham & Sarah, Isaac, etc. all give dates that correspond to the event that is described in the same verse. At least, this is entirely the implication, as again, why even refer to a date if there allows such a discrepancy between the date and the event (almost double in the case of Terah and his sons).
The only thing that I can offer, is that there appears to be another anomaly in Stephen's history. He states that God appeared to Abram, telling him to leave his father's land, prior to reaching Haran. Whereas the Genesis account has God appearing to Abram for the first time, while he was in Haran. Sorry, I don't actually have a point here, outside of a suspicion that Stephen's account is somewhat loose or misinformed (Stephen's ignorance does not necessitate lack of inspiration on Luke's part). But, on the other hand, Acts does say that Stephen was full of wisdom and the Holy Ghost,...????
Acts 7:2-4
7:2. And he said, "Hear me, brethren and fathers! The God of glory appeared to our father Abraham when he was in Mesopotamia, before he lived in Haran, 3. and said to him, 'LEAVE YOUR COUNTRY AND YOUR RELATIVES, AND COME INTO THE LAND THAT I WILL SHOW YOU.' 4. "Then he left the land of the Chaldeans and settled in Haran. From there, after his father died, God had him move to this country in which you are now living.
Genesis 12:1-5
12:1. Now the LORD said to Abram, "Go forth from your country, And from your relatives And from your father's house, To the land which I will show you; 2. And I will make you a great nation, And I will bless you, And make your name great; And so you shall be a blessing; 3. And I will bless those who bless you, And the one who curses you I will curse. And in you all the families of the earth will be blessed." 4. So Abram went forth as the LORD had spoken to him; and Lot went with him. Now Abram was seventy-five years old when he departed from Haran. 5. Abram took Sarai his wife and Lot his nephew, and all their possessions which they had accumulated, and the persons which they had acquired in Haran, and they set out for the land of Canaan; thus they came to the land of Canaan.