And, I figured it out! Mike d'Abo sounds like Tjinder Singh of the English group, Cornershop! I did some research, and they are not from the same part of England. Singh is from the West Midlands (Wolverhampton) and Leicestershire. D'Abo is from Surrey (Southwest of London.) Plus, Singh is of Indian ethnicity, while d'Abo's ancestry is Dutch.
Anyhoo, I still think they are twins as far as singing. Perhaps, Singh is a big fan? What do you think?
P.S. Mike d'Abo later went on to write Build Me Up Buttercup, which was a massive hit for the Foundations.