One often sees eggcrate return air grilles in vintage homes...smashed to pieces and missing parts. Sadly the construction quality of yesteryear's designs was sadly lacking. The reproduction grilles have much tighter joints, typically.
Although we don't show them here, if you are laying a new wood floor and you are looking for an eggcrate flush mount with frame eggcrate unit by all means give us a call. We can make those. Also, sometimes people want the sides to be straight up and down rather than the typical rounded edges. This is often done in commercial jobs to use as partitions or other decorative elements. We can do that as well as no additional cost. Ask.