I didn’t remember that it was marked Webster with the Webster Hallmark until I took the photo last night. I think you may be right that is an assay mark. Seems to me in my search for what the ‘ A’ meant, I think ‘ A ‘ represented .925 silver. You jogged my memory that I saw that ‘ A’ somewhere in the research of Hallmarks. I would like to ask you another question. I have another sterling silver tatting shuttle by Nussbaum and Honbold sp? that appears to be hand engraved. I know it is not embossed. I have attached a picture and I look forward to hearing from you. I will eventually learn how to use this board