Seems like it's pretty close and I can just drill in the connection to the input jack, yeah? I'm not sure what it's supposed to look like, but if I just need to feed a wire from the input jack to the area for the electronics, then I should be good.
I took a similar approach, then drilled a pilot hole with a 5mm bit, to make sure I was in the right vicinity. Then I opened it up some more with a 10mm bit, before giving myself some extra room just in case.