It's been about a year since I looked into this.

There's someone in SoCal who has a patent on cutting down after-market LCD panels. I contacted him directly and was told that success depends on how the original panel was fabricated. I could send him one panel and he would cut it down for something in the range of $1000-2000 with no guarantee that it would be functional in the end. As an alternative, he suggested I contact some of his licensees in Asia so I tried that.

Their prices were better but they were only selling certain sizes. They would consider cutting something custom for our use but were trying to steer me to use an existing panel they were already offering. The cost of the cut panels in volume was around 3x the cost of standard panels.

I was mainly interested in this for installations where the tall LCD just wouldn't fit, but using their panel would require changes to our controller board and there was no record for reliability once the panel had been cut.