I can't think of a comparable example for American glass. If anything, the reverse would be more likely. For instance, Pairpoint usually did not mark their glass unless it was requested by the customer. I can't think of any American examples where a company usually marked their glass and was requested by the distributer to leave it unmarked. There are also instances where a request was made to mark the glass differently, such as Loetz having to mark their cameo glass with a French name for their clients in France, or Libochovice glass leaving off their name and using a registry number for the British market. And many examples from Italy and Bohemia where a glassmarker who never marked their glass would be selling to an importer who added their mark. This Royal Brierley vase is the first piece I've owned where it would normally be signed, but is unsigned at a dealer's request. Learning something new every day!!