20: Corkscrew-tailed animal
25: Unsuitable for surgery
30: Put a counter to zero
33: Physical therapy technique
37: Van Gogh's love offering
38: Professionals who might get your back up?
51: Emergency workers said camper exploded (10)
56: Strong coffee, slangily
60: Mathematician Andrew who proved Fermat's last theorem
65: Responded to reveille
66: George W. Bush, to George H.W. Bush
68: Witches' brew beasties
69: Minor player, so to speak