Mounting the bevel gearbox directly to the chassis and putting it inside a "tin box" alongside your hip cannot be ideal for a quiet result. If you put it on rubber mounts the tensioning of the drive belt will be interesting. Not a matter of a simple fix at a guess but nice to know that Morgan are at least looking at a fix, even if it is a couple of years late. Just sticking rubber padding around it may help a bit I suppose. Not so bothered about the noise if it stays the same and keeps working.