I believe you can get a chunk of glass cut to fit the inside of the faceplate. Not too big a deal there.
But there are labels for the controls on the glass that would need to be put on the glass. A steady hand of a calligrapher, some stick on letters, some acid etching (as is done to car windows with the VIN) would all provide the information. Don't know how good it will look.
I need to investigate these options as my 1120 glass, intact as it is has no control labels on it. I'll never know what knob does what.
The 1120 has the electrostatic speaker switch position on the speaker selector that the lower units don't have so that glass is unique. Using the faceplate of one of the lower units would not announce the dual turnover frequencies of teh tone controls, either.