Help: SR4HH Set up/buzzing

So I’m still having trouble getting this one set up. I hate asking questions regarding setups on forums but I’m getting pretty close to having to take it to a tech, something I’ve not had to do for many years as I’m usually pretty good at sorting it myself.

The symptoms are: buzzing, all over the neck. I’ve had it in every position possible, shimmed neck, remove shim not needed.
saddle heights are nice, and the relief in the neck is generous but not too much, action is a little higher than I’d like but cant get it any lower.
It’s playable but only just.
Any thoughts and suggestions appreciated.
It’s going to be a few weeks before I can get it looked at if it comes to that