Dr. Frackelton was not pleased with the pale color of the 1st printing and ordered a 2nd darker printing. The 5-cent grey and red stamp is very difficult to see the difference. However, the green .10 and blue .25 stamp is quite noticeably darker.  The stamps are a simple 2 color design rectangle shape. And that is where the problems began. Within a few months the USPS sent a cease-and-desist order to Dr. Frackelton as the stamps could be mis-taken for regular postal stamps and thus the USPS would lose sales. This issue was designed by Dr. Frackelton.
RSI 7 - .05 cent stamp - "Map of the Islands" - Perf Stamp
RSI 8 - .10 cent stamp - "Ford Tri-motor Approaching Island"
RSI 9 - .25 cent stamp - "Boat & Dock" - Perf Stamp
The Imperf set is Catalog Numbers RSI 10-12