Lightly Challenging, Highly Specific Birthday Puzzle

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Across
  1. 3. Racket game to be conquered at age 75
  2. 5. Non-visible energy that said grandfather is surrounded by.
  3. 6. Baked good said grandfather is famous for
  4. 8. President when birthday boy was born
Down
  1. 1. Wise lizard who is the same age as the birthday boy
  2. 2. Cozy compound where family lives
  3. 4. Curmudgeonly cat with a picky appetite
  4. 6. Best grandfather in the world, colloquially
  5. 7. _____ Potter: Granddaughter's favorite book