Willard 'Big Boy' Rader posing in 1930 Cadillac racecar

View of Willard 'Big Boy' Rader, posing in a 1930 Cadillac V-16 racecar. "Cadillac V-16 official car, Indianapolis Speedway" is lettered on spare tire. Label on back: "The official car of the Indianapolis Memorial Day Races, a sixteen cylinder Cadillac phaeton (body by Fleetwood), assigned to Colonel E.V. Rickenbacker, chairman of the Contest Board of A.A.A. and president of Indianapolis Motor Speedway Company. Willard (Big Boy) Rader, formerly a familiar figure in automobile racing circles and now in charge of Cadillac's experimental garages, is at the wheel. The car was specially equipped for official use, and specially designed for high speeds." Handwritten on back: "1930 Cadillac V-16 Series 452. One-off sport phaeton, Style #4260-A. Note: The Fleetwood sweep panel, dominant on this car, was not seen on the production phaetons, too, this car does not have the straight-through belt molding found on Style #4260 cars. Rather than the usual leather, the upholstery material was Bedford cord, perhaps somewhat impractical for a completely open car. By Fleetwood. Note this date stamp, 'May 31, 1930.' The most often encountered story, all these years after the fact, is that Willard 'Big Boy' Rader posed for Cadillac publicity shots with this car at the time of the 1931 Indianapolis Memorial Day Races, but that the official pace car for that race was a Cadillac V-12 roadster, etc., etc., etc. But what about the 1930 date stamp ~ does this indicate the car's involvement at Indianapolis in 1930 rather than 1931?"