Blue Seal © 1931 Watling Mfg. Co.
Nickel Play. Twin Jack Pot. Front Vender.
Style 72
Selling price by years :
1931 - $95
1931 - $85
1932 - $75
1933 - $65
1934 - $60
Also released as a Dime Play model called "Blue Seal [Twin Jack Pot] [Front Vender] [Style 82]", and as a Quarter Play model called "Blue Seal [Twin Jack Pot] [Front Vender] [Style 92]".
Collector's Treasury of Antique Slot Machines from Contemporary Advertising - Peter Bach - Page 63, 64, 83 & 122
Loose Change Blue Book for Slot Machines [4th Edition]