It will tend to increase in value some if the handle is nicer than the original one. However, if you spend a lot to make and install a custom handle, you might not get that investment all back when you sell it, just depends.
Some people love a blingy custom handle, others not so much...
Admittedly i would really love to see your Takeda and how it looks after 11 years of dedicated use.
I am always trying to find what old gyutos look like.
I have used over 20 knives in the last 4 years at home so they barely get any wear and tear.