I wonder why he never tried competing at a high level.
My guess is that his ego would be crushed, from being defeated by smaller but better-conditioned bodybuilders.
I remember reading an interview with Rich Gaspari in MuscleMag, in which Gaspari claimed that he beat Richards in a teenage competition and Richards threw a fit.
Richards claimed that there was a conspiracy by the "powers-that-be" in the NPC to not place him properly, because of the guest posings gigs he often got, despite not being a pro. So, to stick it to them, he used his dual-citizenship status and won the Nigerian National Championships and was granted pro status, as a result.
He has not competed since that time. And, I don't recall any other Nigerian National champ being granted pro status. If I am mistaken about that, please let me know.