Got some ideas kicked over from clan mates, and my Alor 'ad suggested trying to make the chest and ab plate be of the same material.
I was initially inspired by Seugtai's kit (like many others before me) and was set on keeping the leather cuirass for material variation. Adds contrasts and layers to the kit, artistically and literally

However, the more I contemplated the aesthetic in my head, the more I was curious about how it would look...worst comes to worst, I can just keep Plan A.
I did a little research on styles of chest plates since almost every EC I could find are all very unique. So I reference a few to help springboard the idea and settled on a hybrid of a couple of the designs.

Got a good template cut out from poster board and traced it over 3m sintra, then took the heatgun and shaped it over my frame. Did a quick test fit with the template to make sure it didn't clash with the belt or collar area.


Put on a thick, uneven layer of Platinum Patch to act as the armor texture. This is like a very strong wood filler; sandable, paintable and good for outdoor/indoor use. I sort of treat it like bondo-lite. It is water based, can be diluted for easy spreading and doesn't have an offensive odor.
After it dried I took the orbital and palm sanders to it to smooth it out roughly with 100 grit, then again with 400 grit. This created a lot of texture variation with minimal effort, but also removed the need to be overly concerned with the detail, which is important when trying to emulate an organic texture.

Once smoothed out, I applied washes of brown and black to age and weather the armor. Always a fun part.

After getting the look I was aiming for, I sealed the washes with a few thin clear coats before getting out the airbrush. I used the same colors I used for the aging step and deepened the tones on the cracks and grooves to give it some more contrast.
Thanks for the insight on bone aesthetics, Vercopaanir.

Looks like I am rocking bone armor all around, very glad that I took the plunge. Critiques and feedback from my fellow mercs are always appreciated.