Nice work.. Back when I did Nascar collecting, I purchased some furniture that was made for diecast cars to be put inside. One was your usual 6ft x 4ft shelving surround and one was a nightstand. It has a front door that opens up and slide the cars in or just raise the glass insert from the top.
Heres a new example to something like the shelving one:
http://images.qvc.com/is/image/c/67/c1767_d48.102?$moreviewmain$
Heres a site that has all sorts of acrylic displays, perhaps something for a card collector might be of interest:
http://displaycaseart.com/acrylicshowcases.html