ALR - I grew up an Astros fan living with my grandparents in the Houston area. My grandmother had autographs of Mantle, Mays, Aaron, and Gibson that I have since inherited. She always told stories of Bob Gibson and how damn mean he was. So i picked Gibby 7s honestly because I knew they'd look good and I could still pick up a 59 for a fairly reasonable price. Though they seem to be rising lately. Plus I kind of like to pick my poison as to what makes the card a 7 instead of an 8 or 9.
Here's an extension of the Gibby collection story.
Varsity Collectibles
Stache - Good luck with Yount. With 17 cards to complete the basic Topps set, the collection has taken some time. And of course I've saved the most expensive for last. Here's a link to the collection so far.
Gibby 7s