Michael Brennan

There are some good documentaries on the VHS underground... like this one. I have fond memories of going to the video store and looking at all the artwork used for the movie cases and posters.

Not exactly what you are looking for... I would be tempted to model a cube 254mm x 254mm x 1000mm or more high then match the cube to the camera view as best as possible. apply some ruler decals to the edge of the cube to see the measurements.