Not familiar with that mark or anything close, (*) EE would almost should be EP maybe, that would be a guess, and maybe a hard to read Williams. Could you post a pic of the entire tray that may help a bit. I also was wandering where the hallmark is on the tray, lookd kinda like on the outer rim, and not the usual bottom. Then from the pic of the hallmark looks real small, and or maybe a engraving rather then a stamped hallmark, but this could just be bad eyes.