WEM Custom 15

[Bushbaby]

One thing I have noticed about this amp (which is working well) is that the front metal speaker grill started to rattle badly as the volume is increased (not by much either). I did put some two sided black tape of the cabinet front but it doesn't seem to be working. Perhaps the change of speaker (10" Fane blue alnico) hasn't helped either (it has a wee bit more bass now).
Does anyone have any thought how i can get around this? I don't what to loose the grill as part of the originality of this old amp.

Many thanks

Rob