The Norton 'Shout!' LP has Louie Louie and also I'm Gone by The Nomads. Just checked, Roman's vocals are on both tracks! Sounds like he was a Taj Mahal type of guy.
I see there is a white guy recently using the same name, also vocalist, as Roman Williams & the Prey. I can't find anything more either about the Nomads Roman (and lord knows there were so many Nomads groups just in the '60s).
You might like this, although mostly about The Gallahads doo-wop style group...
http://historylink.org/index.cfm?DisplayPage=output.cfm&file_id=8710
A few NW bands had black singers, Tiny Tony with The Statics being probably the most famous, and there was Night Train Revue, The Shantelles, and Bobby Taylor and the Vancouvers to the north.