Buff, R.C.: Claudio's Mysteries ©1942 R.C. Buff Softcover, manuscript, 8.5x11", 12 pages

Image courtesy eBay seller JayAndLefty

Comments: Copyright date courtesy Genii's Magicpedia

Contents (from eBay description, numbers are not page numbers):

1 A Silk Routine
2 The Vanishing Glass
3 A Mental Tip
4 A Modern Thimble Act
5 Impromptu Rope through Neck
6 Bobby and the Birthday Rabbit
7 Spirits Are About
8 A New Boomerang Routine