Indium tin oxide coating
There's quite a few options for plating glass to make it conductive, not sure if many will be available for a lowly hobbyist though. Let me know if you know of any.
I do want to keep a window though, it is a tube amp and is too pretty to keep covered up.
There's a few conductive tape options, but I don't know of any that offer EMI shielding capability and retain transparency. The only ones I know of only offer z-axis conductivity, but not x and y, which is not helpful for emi shielding.