It is a clean install but so why such a large port for 2 wires? Why not have the vim installed inside the plasma cabinet and then use a small barrel connector port instead for the divide single output from the VIM? Then all the full dc voltage wires will be contained in the plasma cabinet. Just a thought I wanted to throw out there.
A few examples
Edit
Or leave the vim In the plasma Cabinet and use the factory CNC port by removing the factory divided voltage connections from the plug and then solder on the output from the Vim to then instead. No new holes. ?
A lot of ways to skin a cat.