Hardening chrome-tanned cowhide.. HELP?

I'm attempting to make Cloud Strifes pauldron from FF7-AC. I originally thought I'd make it from PVC, then line it with leather. The issue was bending the thick as fuck PVC at the point nearest Clouds neck into an upward position without bending the points other than intended, thus concluding I shall not line the PVC; merely shape and harden the leather itself.

The leather is, as stated in title, a chrome-tanned cowhide of 1/8 inches in thickness. I only need to know an appropriate firming/stiffening process that I may apply to this type of leather/tannage in order to achieve the result I'm seeking. I assume that conventional water will not work as it is generally used for vegetable tanned leathers.

Any help is appreciated.

 

Banned for self vouching with 2 other accounts......