Based on your description of the hubcap emblem, I
think it might belong to a Peugeot car. Peugeot is a French car
company that has been using the lion logo since 1858. The castle crest
you mentioned is actually a coat of arms of the Franche-Comté region,
where Peugeot originated.
Peugeot hubcaps from the 1930s to the 1960s had a full-wheel design
with a chrome or nickel finish and a dome shape. They also had the
lion logo and the coat of arms on the center, surrounded by the word
Peugeot or the model number.
???
This is a response to the post seen at:
http://www.jlaforums.com/viewtopic.php?p=465678072#465678072