Hello David you solved the mystery! On the page that has Pleasure of the Sea.If you enlarge the picture you can sea the skeleton key on top of the mask.I really didn't think this was a U.S. made mask.The earlier one that sold on ebay way back wasn't the second oldest mask sold in the U.S. accoriding to the HDS joker either.I have other early U.S. masks beside Sea Net mfg that are from the 40's.Great job again.Thanks Mike.
Well, I never! You fitted the last piece of the jigsaw puzzle, Mike, by enlarging the picture and spotting the skeleton key, which I missed. Well done too for remaining sceptical about a US source for this snorkel-mask, considering the use of aluminium to construct the snorkel. As a Brit, whenever I think of aluminium snorkels of the 1950s, I always think first of Made in England Typhoon breathing tubes such as the T1 model below:
Even so, the use of aluminium for a combined mask and snorkel tube may be unique.
Hong Kong was a British Crown Colony back then, benefiting from "Imperial Preference" when it came to trade, so manufacturers there were used to making goods expressly for the British market. UK imports from Hong Kong at that time were often labelled "Empire Made":
However, this wasn't legally required, and "Empire Made" labels vanished from Hong Kong products after the UK joined what was then the European Economic Community in 1973 and Imperial Preference was discontinued. After that date, all Hong Kong exports marked with their country of origin were labelled "Made in Hong Kong", like the Wah Tai Web Feet fins below: