I have two very large stein lamps by mettlach. Have not found anything similar I in size on eBay. I am thinking if selling. We used to have a stein show in Milwaukee but I haven’t heard of one in years.
The Mettlach Book doesn’t list any lamps under Other Wares and I didn’t see any lamps listed in the old Mettlach catalogs. Are you sure someone didn’t convert an old stein into a lamp? Is there a Form Number on the bottom? Photos would help too. There are a couple of Mettlach lamps on ebay, one is a 3,0 L stein, but they are steins someone converted to lamps. A stein collector might be interested in the lamps, but they wouldn’t go for a much as a similar mint stein.
The days of travelling antique shows is long over. It is much easier to do it on-line.