I have four (4) plexiglass acrylic sheets. They are old, in original protective packaging, never used, so they are in new condition. The only drawback is that the protective brown paper covering is really stuck on and I guess you would need to soak it off or goof-off should do it.
(Note: This photo is actually another plexiglass piece I have, so not the ones described above but this is what plexiglass looks like). I'll try to find my other photo and post it.
Dimensions: 15" x 11" x 0.093" The packaging reads:
Rohm and Haas Plexiglass Acrylic Sheet
Acrylic Safety Glazing
ANSI Z97.1-1966/72 .079U