The larger Dynasound Organizer Cassette Tote Case that was used for Geordi’s engineering kit is extremely hard to come by, though the narrower type is found easily enough on eBay.
It was completely dumb luck on my part that I stumbled across an auction for two of the larger case on eBay a few years back. Got them both for a song and dance:
Starfleet Carry Case (link to my YourProps.com page)
Still plan on detailing one as Geordi’s engineering kit, and the other as an LCARS wall panel seen in TNG. Would love to see all the ones @norbauer has