Laura, I'm guessing that you're offering your "or" scenario as an alternative to the theory that the two boys fingered Bix out of anti-German sentiment. I've made it clear that I'm unpersuaded by that theory because it is based on speculation. So, alas, is yours. You suggest that the boys might have been "two working class teenage boys who were laboring in the street at necessary jobs to support their families" and that they "did not have socially influential or moneyed families." I would be very interested to learn of any actual evidence you have for this scenario.
In contrast, the substantial research I've done on Mahlon W. Bailey and James L. Duncan--the two boys who identified Bix--establishes a different picture. The two had been in elementary school together and participated in various activities together in the following years. Bailey, who died in late 1962, was probably 17 or 18 at the time of the Ivens incident. He may not have finished high school, but it seems that by May 1920 he was working for the Linotype Company in Davenport, a going concern that employed a lot of people; in 1923 he was a foreman there. By 1920-21, Bailey was already becoming popular in the community for his amateur singing (baritone), acting, and comedic skills, and by 1924 his photograph was appearing with some regularity in the Davenport newspapers with such captions as "Popular Soloist Will Appear at the Sunday Sing." He was president of the local Fraternal Aid union, and was active in the Epworth League and other organizations. In 1924, Bailey married Dorothy Kress, the daughter of J.J. Kress, president of the Tri-City Tent and Awning Company, for which Bailey later went to work, it appears. (Thus, for anti-German theorists, Bailey seems to have wed a woman with a German name.) The account of the Bailey-Kress wedding ran to three columns on the social page of the Davenport Dailey Times for 1 May 1924. I haven't yet discovered what Bailey's father did, but the newspapers not infrequently mentioned a tea or other social event that his mother hosted at their home at 1105 Oneida Avenue.
The other witness, James Leigh Duncan (1904-1933), was 17 at the time of the Ivens incident. A boy named James Duncan had been expelled from Davenport High School a year or two before, but the name is a pretty common one and I haven't determined that they were the same boy. But the James Duncan who identified Bix was no laboring lad trying to turn a dime for his folks. His grandfather, James Clark Duncan, had been head of the Duncan business college in Davenport. Since 1910 or so, his father, James D. Duncan (1874-1936), had been with J.H.C. Petersen's Sons store, where he came to serve as credit manager and business manager, and later as secretary and treasurer of the Henry F. Petersen Investment Company of Davenport. Young James (the Bix identifier) went into military service, first serving, in 1922, as a stenographer in the office of an inspector general in the Hawaiian Territory, and later gaining acceptance to West Point as a cadet and, after graduating, serving in the U.S. Army Ordnance Dept. In the last years of his short life he married a woman in Kentucky and was studying in a college there to be a Baptist minister. He had a bit of trouble in his young years. In addition to the possible high school expulsion, he served a few days in the Scott County jail in 1926 for bouncing a couple of checks at a Davenport car garage in the amount of $25.90.
So, these were not two kids laboring at odd jobs to keep hard-scrabble families afloat. They came from middle-class families and, despite a mistake or two (in Duncan's case), led respectable middle-class lives themselves. In fact, it seems that Duncan's family was at least the socio-economic equal of the Beiderbeckes. Whatever the police report meant in stating that Bailey and Duncan "were working across the street" from Goddard's garage, it didn't mean what your scenario suggests. Best wishes, Bob