Harley Davidson engraved Waltham pocketwatch. Who was Curly?

Looking for information on this antique Waltham pocketwatch and the past owner. This watch seems to run just fine, but what caught my attention is the engraving on the back of the case. It has a winged wheel (in great detail) with Harley-Davidson engraved above, and "Curly" engraved below with 8-15-21 under. I am guessing Curly was awarded this watch for some Harley-related activity on August 15 1921.
Who was Curly and what is he story behind this great old watch?

[@pitoniakcycle]

Very cool , I collect pocket watches and especially Walthams

[@AntiSup]

I have wrist watch of Waltham with dead second made for USSR by 'Russian war relief' program at WWII. This is nice match with my 1943 lend-lease Liberator Harley :)

[@irishpat64]

Is that the “Indy 500” symbol also?? Could it be associated with that track??