Hi Joe,
Nice Elgin find,
Your bike was produced by Westfield Manufacturing for Sears and is a variation of the Moto-Balloon model they made for several years. The earliest versions have paint schemes with darts and later bikes have the three stenciled stripes and were available in black or red with ivory stripes. The first models that used the stripe paint job were equipped with the earlier stainless rain gutter fenders so your bike should date between 1936 and early 1938 when the model was dropped from the Sears line.
Early Bikes used the Oriole moniker but the later bikes like yours lost their name to another model with a curved seat tube and deep curved down tube.
Westfield bikes can be easily dated by the serial number stamped in the bottom bracket. Relevant to dating your bike; A=1936, B=1937, and C=1938. The five or six numbers following the letter are sequential to total Westfield production which ran approximately 260,000 in 1936, 190,000 in 1937, and 126,000 in 1938. (1938 was a recessionary year and bike production was down across the boards that year. It then climbed steadily until production was curtailed for WW2)
There is likely also a second number stamped in the bottom bracket, a letter followed by one or two digits. This seems to be a year/month code where C=36, B=37, and so on and the month is represented by 1-12. Generally this code agrees with the serial number but a few bikes have turned up where the two do not align.
Also of note, the rack is the standard Sears catalog accessory rack that was available for several years. It is essentially the sheet metal for a Bluebird rack, cut down and put on stilts. The chainguard is also a generic period accessory. Although not depicted in the catalog, Westfield may have factory mounted racks on some of the bikes but the chain guard is more likely than not owner installed.
Phil