Joe, I don't know who selected Limeliters' material, but Yarbrough recorded for Elektra at least as early as 1958, several years pre LL. You can hear him solo and in duet with Marilyn Child on Electra 143.

BTW if the implication of much of this thread is that he was a sell-out, I would opine that his selling out was a lot less of one than many of the 60s group.