It looks as though the connection between the front and back plates and the lower neck ring may be metal riveted to metal.
Yes, the front and back lower neck plates are riveted solid to the mantle, as you can see here:
http://home.armourarchive.org/members/v ... t%2006.JPGI chose not to articulate these plates because I didn't want the gorget to bend toward my neck when I get hit. I may be a bit paranoid concerning injuries, but at 5' 10" and 130 lbs, I'm far from being a big guy and there's not a lot of meat over my neck bones to absorb hits, so I chose to follow the route of safety.
There is a loose rivet holding the 2 piece of the mantle together and allowing the gorget to be opened on one side (you can also see this rivet in the pic).
As for criticism, I find it hard as I don't know what type of harness you will wear with it....
Ok guys, be prepared because this is gonna hurt... I am going to wear it with my mid 15th cent. kit. I know, it is sin, I am supposed to wear a maille collar, but I needed better neck protection for fighting. I could have made a collar-style gorget covered in maille, but I was afraid of the gorget being smacked into my neck (see above). So, this gorget appeared to be a good solution. I wear it under my breast and back plates, so the mantle is hidden, and the rest of the gorget is not too visible because of my barbute, reaching almost my shoulders. Soon I will make an armet and it will have a maille collar hanging from it, completely covering the gorget. So, will you pardon me for not being a good boy

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Thanks for your comments so far, keep 'em coming!