Without knowing the exact size or seeing a close up of the switches up front, stick ur pc parts inside, add a window or convert one whole side into an opaque window. Have that be black when it's dark and light up when the pc gets turned on. Convert the front switches/buttons into the use of a baybus or lights or something. And if that meter works, use it for something.
It would depend on what u needed out of another box. The purpose and use would determine the mod. HTPC? server? router/firewall? normal use? A disguised HTP would require little modding and maybe a brief paintjob to spice up the look. Possibly a VFD or lcd up front? A TB server could involve some pretty lights up front for the hd's and quiet fans somewhere... A router could add ports to the front or have more pretty lights up front.
A Borg Cube theme? or dice? or cube pc mod might be considered.