He has never heard of Best or DeVille. Sounds like Roby hung around a lot of queers even for a bohemian. He hates to pry into how the guy spends his free time but it could be useful information.
Certain universities and museums sometimes contacted Parker, because he could knowledgeably authenticate and identify occult manuscripts, but he hasn't been active in this for the last ten years. He deals in antiques and rare books from his North London address; it takes a lot to get his attention but when you do he's competent and utterly ruthless.
"Parker's a big name in antiques and rare books." Whom Oscar has avoided dealing with as he has a certain reputation for ruthlessness. In any case-- "Do you think he'd be willing to help with Roby? I'd like to talk to him." He hopes Carter has a better read on Parker here because contacting him out of nowhere to ask about an unfortunate friend sounds terrible. Though many things about the Roby business are terrible, comes with the territory.