Many thanks Alan, you may be correct, esp judging from the padding on the helmet. The findings in Google search all seem to be from eBay, without any clear evidence offered for the authentic, intended use of the helmet (beyond what the sellers seem to claim). I’d love to find a photo of a Swedish tanker wearing this helmet.

Your message prompted me to expand my search further, and I’m surprised to learn that neutral Sweden actually had an armored division during WWII and an indigenous tank industry. Looks like I’ve much more to learn!
Thanks Alan!