If you are starting from nothing then there are cheaper faster options I think that would allow the use of the battery.
The problem is there isn't very much room in the base. I have made a 1" extension for the bottom plate and removed the battery case part. That helps have enough space for the battery as well as a controller stacked in the base and doesn't look bulky.
This scooter would be a challenge for someone with little fabrication experience or tools. Its definitely a process to fit everything.