Fror hazy memory, there is a thing called "center trace" somewhere (Inkscape plugin?). I assume Rich will chime in for this.
Otherwise, since your path seems to fall on a regular grid, you can define an image grid that overlays you image grid, activate View ➤ Snap to grid and then drawing your path will be a snap, if you pardon the pun.
Otherwise, since your path seems to fall on a regular grid, you can define an image grid that overlays you image grid, activate View ➤ Snap to grid and then drawing your path will be a snap, if you pardon the pun.