Book and Dust Jacket appear to be 1939A-16 printing per Carpentieri Guide 5th Edition
Author: Franklin W. Dixon
Publisher: Grosset & Dunlap
Copyright: 1931
Book Cover Color: Brown
Endpapers: Orange Gretta
Dust Jacket: minor chipping (See Photos)
Volume No. 10
Glossy Frontispiece
Condition: this pair is in as about of good condition as I have ever seen.
Pages: Creamy white and supple. (See Photo)
Inscription: None
Marks, stains etc.: someone 'painted' part of the clouds on the front free endpaper - see photo