I've never seen an IMSAI before in-person. The
front panel does
not have the white "IMSAI 8080" logo. You can see a silhouette
of it under the Plexiglas mask. Does the logo light-up when turned
on? Maybe this is a replacement mask (although the screws do not
appear to be disturbed)?
If I recall correctly, the "logo" is composed of two parts, one is a
clear plastic sheet with black printing that gives the shape of all
of the letters, switch and light legends, etc. Behind that, there
should be a sheet of foil backed white paper. Those two sheets are
sandwiched between a sheet of clear and red Plexiglas. Sounds like
you are missing the white sheet.
Bill