As a McIntosh Authorized service tech, let me emphasize that you need to fork out the extra bux for the McIntosh original. This will be newly made (they have an amazing water knife for cutting out the plates, which are then hand painted and prepped. Do not remove the old glass until you have the replacement, so you can remember the reverse assembly. There will be a plexiglas light pipe sheet and items to attach to the new glass from the old, it does NOT come ready to install. Use the thinnest double stick foam tape you can buy for the stick on items. Be prepared for several hours of work, and while in there replace bad bulbs, etc. Do not buy the McIntosh lamps, these are cheap Chinese and last only a few months, buy bulbs from Mouser Electronics they will be cheaper and last at LEAST as long.
JUST MAKE SURE THAT IF YOU BENT EITHER TOP OR BOTTOM EDGE PLATE that you straighten it out before installing the glass. I had one come in with shipping damage, didn't realize the top edge frame was also bent, installed the glass, and while I was warming it up for final calibration sitting at the desk across the shop doing paperwork, heard a creaking noise, then a sharp crack as the brand new glass shattered from the bent frame PLUS heat from the light bulbs.
Took about ten minutes to break several hours work. Shop had to buy the glass.