I've never seen one of these things but I ordered it - can it be glued into place on the bottom and screwed on the top (in case you want to change marquees)?
Do the screws show?
Most cabinets I've dealt with have a groove for the marquee glass/plexi to slide into the bottom, and the top has between 4-5 screws on top to hold the retainer on.
Others have retainer on both top and bottom. Screws are used to hold it in. I'd go with rounded black screws (preferably either security or Phillips). Sure they show, they all do. I wouldn't glue, eventually it'll give way.