Hi Wombat, these might help you out.
4, Margaret Mitchell
6. A big steak starting with "p" and a colour
15. Demise after lunch, (E.H.)
16. Somerset Maugham
17. What some people call "frogs" and a stretch of water
33. C.S. Forester (Think of what Satchmo was famous for
36. Nicolas Monsarrat
38. E.T. is a famous actress
39. Think of a famous sherry (Alexandre Dumas)
56. Almost reverse the word "nowhere"
63. A French novel (Pierre Choderlos de Laclos
70. As the title suggests (Sir Walter Scott)
76. Short William + untruthful
81. If you walked up this many it certainly would
92. Another Sir Walter Scott
95. If you were "isolated and alone" you would be "Far....... (Thomas Hardy)
99. Hammond Innes