Fascinating synchronicity. Having looked at your posts old family photos during Halloweens of yore, I've been looking for a certain black and white photo of me around the late 60s, when I was 5 or 7 years old and wearing the exact same skeleton mask for Halloween! Alas I haven't found yet it but somehow you did. Nice link.Frank.
If you're looking to find one of these skeleton masks, take a look for Collegeville "skull" or "skeleton" costumes on eBay. There are many color variations to this mask, as it was produced over several decades, but the basic mask form remained mostly the same. Happy hunting!