There are a number of lusters/lustres like yours listed on eBay right now . The word "antique" is used to describe with no additional information on year or maker. Since Bohemia became Czechoslovak Republic in 1918, and assuming yours are original and not reproductions, you can figure they date at the latest from the early 1900s Victorian period. Check the "sold" ones for more information on selling prices, etc?
Rita
