I'm having trouble looking for this chestguard. It will be perfect for my toon, but trying to find it has been nearly impossible. I know its easier to go to the GTM, but I'm new and not rich like most. Is there a specific place it can get dropped? Any help will be greatly appreciated. Thanks to all that reply

I'm also looking for the chestguard that can be modded. Or the adaptable armor. Thanks again!

Here is a link to a list of people that drop it (I'm assuming you're referring to the non-prototype version):

 

http://www.torhead.com/item/bEpgE9L/rd-13a-raider-chestguard#dropped-by

There are a few variations for that chest (slightly diffferent colors) from crafting

 

On Red Eclipse

Electrum Onslaught Chestguard (lvl 50), cheapest at 10k

Outcast Chestguard (lvl 27, trooper, knight), cheapest one listed at 9k

 

I don't know what server are you on, but maybe if you check regularly the gtn, or perhaps ask for a crafter on fleet (i believe both armomech and synthweaving should have the ability to craf it)

The RD-13A Raider Chestguard has a yellow/white color scheme.

The Electrum Onslaught and Outcast's chestpieces (craftables) are green/cream and blue/white color schemes respectively. The second(?) boss Hammer Station story mode can drop a similar chestpiece that is orange/white. May be useful to you.

There's another option, the Ultrachrome Onslaught Chestguard, which is a reward from the Heroic 4 The Tyrant on Belsavis. Kinda greenish/grey....