I think you're on the right track, Candy. Upper or lower case for an eponym is largely a matter of personal preference, but it also depends on how great the remove from the source. I think it would be difficult to refer to a boswell without a mental nod to James of that name, but a fleet of diesels can roll down the road without anyone giving a thought to Rudolf. How many athletes routinely dress in a jersey with no awareness of the island from which it takes its name? There may be strong opinions on the capitalization question, but I doubt that it can be boiled down to a rule.

Peter