@AndrewJohn, you could do these yourself. While not difficult, it is a time consuming task. Going to be very similar job as I did on my MG 1's. Process would be the same. The buzzing is likely either coil loops lifted, hole/s in the mylar film or a combo of both. To fix any holes in the mylar; you need some mylar tape (Scotch brand), 3M 77 spray adhesive (to hold down the tape and wires) and some Milloxane or 3M Fastbond (to seal the repairs). Definitely doable.