1: Tutus can serve to conceal Donatello, Leonardo, Michelangelo, and Raphael, say (7)
5: Merit in rum tasting more like a julep? (7)
8: With great strength holy man stays above reproach (9)
9: Linguistically rich, having the words (5)
11: Drink to them, not with them. (6,7)
12: Yes, MBAs worked with a diplomatic staff (7)
14: Apparently observed a part of the play (5)
17: A group performing with energy 'The Untouchables' e.g. (5)
19: Troop of monkeys around city garden spot (7)
21: Ships use up aid at sea; remain in a grave situation (4,2,7)
24: Belonging to you, is getting to me, Herb (5)
25: That may be reversed, but his son sits around pointlessly. (4,2,3)
26: G-man covering beat lit up Bic? (7)
27: Thelma's abandoned small towns (7)