Today we will address a subset of the 1930's Parker pens that in general have been lumped by collectors under the "Thrift Time" label, but which in this specific case resemble-- to a point-- the 1934-1939 Parker Challenger and Parker Deluxe Challenger pens. Often these have been mislabeled in sales and in discussion as Challengers. But, there are differences, starting with the very imprint Parker placed on the "Thrift" pens in question. In fact these Challenger-like "Thrift" pens are well less common than their Challenger siblings, and documentation for them is sorely lacking, leaving us with speculation and contextual guess work to explain their existence.
Parker's so-called Thrift Time pens comprise disparate models manufactured from 1929-1938 or so, generally quality button-fillers less impressive than any given premier series in concurrent production. A unifying feature to these pens is the presence of a bland, "Parker Pen" barrel imprint, lacking the model name present on most Parker models from that era. However, do note that the term Thrift Time Pen is not from Parker, but rather is collector jargon developed in retrospect, based apparently on the presence of a Parker advert from 1931, which shows one of the many nameless "Thrift Time" models, while intoning in the advertising shpiel, "In these thrifty times…".
The collector term "Thrift Time pens" proved a convenient way to lump together pens lacking barrel model imprints or for which model names were not available to collectors. During the last thirty years, some information has come to light about some of these pens, so some of the pens today have model names or at least Parker descriptions available. Still, many collectors keep the pens under the "Thrift Time" umbrella. Thus, collectors can discuss Parker's Thrift Time pens, but should realize that-- really-- there are no Parker Thrift Time pens.
Shown below are several varieties of "Thrift Time" pen. The last two on the right likely are related and are the focus of our attention today. They resemble slender size Parker Challenger and Parker Deluxe Challenger, thus it is fair to call them Challenger-like Parker "Thrift Pens".
Look at the last two pens. The red mottled pen has a 1937+ blade style clip. The final silver mottled pen has the ball clip seen 1934-1937 in this series (and in Challenger in Deluxe Challenger).
Do not worry about integrating all the pens. From here we will examine just the Challenger-like varieties.