On Wednesday, August 30, 2017 at 3:57:16 PM UTC-7, Dave M wrote:
Anyone have experience in accurately cutting 1/8" thick acrylic Plexiglas
(Perspex) for LED displays?

....

Any suggestions as to a good, safe approach to cutting the plastic?

Dave M
All of these suggestions were interesting, but when I wanted something similar, my local plastics stores were willing to cut them to my requirements. This worked both in White Plains NY and San Jose CA. I tried your dimensions on the TAP Plastics web site, and it was $10 for one, $14.90 for ten, and $149 for a hundred (ISTR that the onesies price was lower for walk-in service, especially if you could find suitable stock in the scrap bin so you would only be charged the cutting fee). I vaguely recall that they used a band saw, but it has been more than thirty years.