I think you are good. The high percentage of Rebel IV is a good sign--top quality cultivar. Lesco brand is a good sign--they would not risk their reputation with a blend that had a yellowish color component. Remember the seed may lose a few (say 2 percent for example), percent germination per month--especially if stored under poor conditions,,,such as hot and humid. Ask if it was simply stored locally in their warehouse--or--at the seed producer's refrigerated, humidity controlled-warehouse in Oregon.
Slit seeder is better than an aeration machine. For less than optimum conditions...only half the seed may survive, use more seed...such as 10 pounds per thousand...particularly if you have dead spots or extremely thin areas. Perhaps go over such areas two or three times. Mow short before beginning so that the new seed can receive plenty of sunlight, and therefore not be crowded out by old grass.
I am not sure if starter fertilizer is a good idea or not. It stimulates new seed--but also stimulates the old grass.
Most important!!! Plan to irrigate every day for 30 days.
Tell us how it works out in 8 weeks...OK?
I am sure we will have many more similar questions and situations coming up soon. The dryness and heat was brutal during the summer of 2012.