This is my current project today. My Primus No.51 with a date stamp of AB/32. From what I read it should be a 1937 date according to the "AB" but I do not know what the "32" is for. I am sure that someone will correct me shortly if I am wrong. It currently is using the recently acquired aftermarket Liberty burner due to the burner that came with it having some issues that I am trying to solve. I have included pictures of both burners just for reference.