Ras 422,
I always thought that The Showmen were overlooked. Everyone hailed Brian Wilson when he fused vocal music (doo wop) with Chuck Berry, Cal sunny lyrics and his own lunatic production vision. Meanwhile, over on the East Coast, Allen Toussaint was doing something similar with Johnson and The Showmen - but in a low key manner that lacked the production values. Even though the music had IMHO more emotional resonance, no-one seemed to notice.
Johnson got his due later with The Chairmen of The Board and a more Motown approach. He also wrote "Patches", my nomination for the best truly bad song ever written.
IMHO, Johnson's a great singer and generally cool guy who had a great, largely unappreciated contribution to RnR over its first two decades.