Perhaps the Medallions did inspire the Beach Boys and Jan & Dean. The Medallions were from Los Angeles and the Beach Boys and Jan & Dean were from nearby Hawthorne and Westwood, respecitively. The Medallions were popular in the LA area as were several artists on their label, Dootone.
I’ve seen Vernon Green, the Medallions’ lead singer perform on two or three occasions. He would walk with a cane—I heard that he had been crippled by an attack of poliomyelitis. The last time I saw him perform, he was in a wheelchair. This was in the late 1990’s, shortly before his death in 2000.