1958/59 Emerson 888 series
The original Emerson 888 — the one without any name attached (not shown here, though its cabinet face is identical to the "Pioneer" model shown here) — was most likely released in 1957. These four models here were produced in 1958, and maybe 1959 as well. All four were named after the pre-NASA-era rocket programs of the US Air Force, Army and Navy. The leather-cabinet "Satellite" 888 also was produced around this same time, as was the leather lunchbox-sized Transitimer 888 clock radio. All the 888 models were considered to be good-performing transistor radios in their day.
The plastic used for the 888s' cabinets was not nylon — a simple solvent test shows this: ketones such as acetone and MEK have no effect at all on nylon, but on the 888 cabinets they soften the plastic (see my "Plastics" page). Exactly what this "Nevabreak" plastic was is still unclear, though I think the plastic used on the 888 cabinets may have been Cellulose Acetate Butyrate, the same plastic used on the Emerson 555 — these cabinets (the 888s and the 555) are even softer to the touch than is nylon.
The four chassis examples shown below have some minor differences between them in component layout and complement as well as in the transistor complements. With the exception of the Explorer's special tuning dial arrangement, these of course can be assumed to be differences between these specific examples only, each produced at a different time, rather than differences between models.
Click on the photos above for pages of each model shown.