12-strings model design modification

I changed the body construction for 12-strings model. This is for minimizing a body deformation issue. I have been observing substantially serious action change issues for the 12-strings model. This is due to the strong string tensions. To minimize the body deformation issue, I installed two massive graphite rods from a top of the head block to the bottom of the body wast. This design is not my original idea. Similer techniques have been seen many hand made guitar makers such as Mike doolin guitars and McKnight guitars. I followed those ideas. I hope this design modification improves the action change issue.