Here's the message I have created:

19 16 19 15 23 16 24 11 11 24. 25 19 25 19 15 16 11 16. 25 19 25 19 15 25 16 26 19 26 '24 12 25 12. 26 19 26 15 19 29 23 25 23 25 16 30. 12 25 12 19 29 14 11 14 25 16 30. 12 25 12, 11 14 11, 26 19 26, 11 23 25, 21 19 25, 11 30 11 22 11 24 14 12 15 12 15. 11 22 19 29 26 25 26 25 16 30. 11 22 19 29 14 11 14 25 16 25 12, 30 25 25. 12 15 12 15 19 29 24 11 24 1 25 16 30. 12 15 12 15 19 29 23 25 23 25 16 12 25 12, 30 25 25. 30 25 30, 25 19 30, 11 22, 12 15 12 15, 26 19 26, 11 22 24 14 12 15 12 15. 26 19 26, 11 23 25, 17 25 30, 25 11 22 '24 12 15 12 15. 21 19 30, 11 20 20, 11 22 11 24 14 15 25 26 25. 12 25 12, 11 14 11, 17 25 30 15 1 22 '24 12 15 12 25, 30 25 25. 12 15 12 15, 11 24 1, 19 29 1 30 1 22 1 24 14 15 25 25, 11 22, 26 19 26, 25 19 19, 12 15 12, 19 11 24 14, 11 22 1 12 1 30 12 24 15 15.

This took lots of thought, although I don't think I have made an encoded text that will stump anyone.