Still a little concerned about a buzzing I have when I plug the harness in to test that goes when I turn down master volume or tone. Maybe nothing I can do about that as I can’t shield the hollow body.
It sounds likely to be a ground problem.
Are you grounding the harness in anyway when testing it? Just contact with your body should do it.
Sheilding won't fix earth/ground noise. Sheilding is about RF.

If you like to buy Australian made hand wound, look at Mr. Fabulous and Mick Brierley pickups.
I think they'd go beyond his budget: "And not looking to blow the bank either"