Only guessing when I say part of a as issued body armor harness kit. Did read about a few different styles today. Kits may have been assembled in field from different makes and countries, using about anything you could gather.
Replies already posted are in line with the top concern..... protecting the family jewels... True Read That !
Anyway- This picture seems the closest so far to me. With your find possibly being either the front chest or back piece. If so, I'd lean toward the welded stubs and swinging latch being used to help attach gear (?)
https://www.milsurps.com/images/impo...onattach-1.jpg
Picture was found here:
WWI American Body Armor. - BODY ARMOR - U.S. Militaria Forum
Also to note:
Commercial versions of body armour were also available and family members took it upon themselves to buy armour for their loved ones and have it posted to them abroad.
And that was found here:
Armour for soldiers - WW1 East Sussex
I find it very interesting, only wish I could be more help.
Good Luck,
PS: A link to some WWII gear. Possible any of this was left over from WWI ? Or Re-designed for WWII ?
MRC body armour in Canadian use during World War II | SpaceBattles Forums
https://www.milsurps.com/images/impo.../gYAMo1J-1.jpg