"J"-hook style crest

[Gaivs Antonivs Satvrninvs]

Thank you very much,Stefanos. I had just finished reading all posts pertaining to this when I saw your post. Unfortunately, there's still no real dimensions given but some very good pictures of re-enactors and pottery.
I'm thinking it should be about the same height as the helmet and around 3 or 4cm deep. Maybe 1.5 cm thick. Sound about right to you?
Thanks for the help. Great to hear from you.