I went to high school with a guy whose father owned an acrylic display case company. I Googled the name and it looks like they sold the business to another company in 2007.
Here's a link.
http://www.carneyplastics.com/home
I don't know if you have come across them or tried to ask them. Or if they'd even do it for you. It seems like a fairly small project but I don't really know anything about the material or process involved.
It's been 20 years at least since I saw the guy I knew and around 10 years since his father owned the business. I remember at the time they could make just about anything. Mostly display cases for diecast cars and countertop displays for small businesses. He loved fishing and had a giant display case for his fishing lures. Ahh memory lane...
Anyway I hope you find someone who will take your project on. You could get a piece and tinker with making one maybe?