JackRussel,

Welcome to NeuroTalk. You may never get the last 15% back. Research shows that brain injuries never heal 100%. The residual limitations can be worked around with a variety of learned skills.

Your age is a big factor against brain healing.

The only thing you may try is learning to play a musical instrument. It works a different part of the brain. It is not a proven technique but may be worth a try.