Glad you got it working. Using the neck pickup is a good idea as it will have a slightly lower output than the bridge pickup and so will match better in levels with the single coils.
I'd be tempted to try fitting a pickup ring around the humbucker. A thin flat one would do it and it would make it a bit more individual whilst still hiding the rough edges of the hole. But looking at your picture, I'm not sure that there's enough space between the lower edge and the volume control knob to fit one.
If it was me. I'd get annoyed with the hole after a while and have to get a new scratchplate.