“The fact that this monstrance is brass is a very good indication its post VC II.”
(sigh) No, it really is not.
http://www.christies.com/lotfinder/lot/a-19th-century-brass-and-paste-set-4277616-details.aspx?intObjectID=4277616
http://www.fluminalis.com/inventory/monstrances/monstrance-style-barok-en-brass-silver-france-18th-century-902644