"Illustrated exterior with four boys in front of two arches, may be first edition, shows no additional printings. No jacket. Some soiling to tan cloth binding. Solid binding. Interior pages mostly clean, but has a small stain on pages 49-53 (coffee?). Pages a little tanned due to age, mostly along edges. Gift inscription on flyleaf. 247 pages+ ads. 5.25x7.5x1"" Book #4 of the Radio Boys series. Jack Hampton, Frank Merrick, and Bob Temple journey to South America in search of adventure and treasure. Vintage boy's adventure series."