Changing registry name (id) for custom chestplates and leggings

I've made several armor sets, and I have them appearing in game as I want them to, with textures all in place, the items having the right display names ([custom] Helmet/Chestplate/Leggings/Boots), but as far as the item id goes for the chestplates and leggings of these armor sets, they're all in the format of ("maatm" is my mod's prefix for all the items within): 
"maatm:custom_body"

and

"maatm:custom_legs"

This obviously doesn't match up with everywhere else the two armor pieces are listed as chestplates and leggings, and doesn't really make sense, especially when using the /give command in-game. Is there any way to change this? Or are the chestplates and leggings for all my armor sets doomed to have the "body" and "legs" suffixes?