From MagicPedia

Mysto Magic Sets
Mysto Magic Sets were sold by the Mysto Magic Company started by A. C. Gilbert and John Petrie in 1909. The company would later become the A. C. Gilbert Company. Most magicians born at the beginning of 1900s remember the first Mysto Magic Set they received as a kid, sparking their interest in magic.

Contents
1 Mysto Magic Set #1
2 Mysto Magic Set #2
3 Mysto Magic Set #3
4 Mysto Magic Set #4
5 Books
Mysto Magic Set #1
Sold for $0.50

Mysto Magic Set #2
Sold for $3.75.

Mysto Magic Set #3
Sold for $12.00

Mysto Magic Set #4
Sold for $25.00 and contained the following tricks in a wooden box with nickled corners:

Wonderful Card Act
The Bran Vase
Mirror Glass
Flag Between Handkerchiefs
Flying Handkerchiefs
Great English Egg Bag
Combination Wand
The Magic Vase
The Peerless Monte Crest Cards
New Remarkable Handkerchief Trick
The Excelsior Rope Tie
Confetti - Yetti
Combination Shackle Escape
Sealed Letter Reading
Multiplying Billiard Balls
The Pull
Book of instructions for twenty additional tricks requiring no special apparatus as well as hints on presentation and an article on legerdemain.

They are very collectible items now.

Books
MYSTO A conflict of dreams By Nelson C. Nicholson (2004)