@nowlan,
You make contact with the seller via the ebay messaging system. I included my telephone number and he phoned me !
These catches are found in many applications.... TV hidden control panel covers, Gas Boiler control covers, car pop-out draws, panel mounted printer thermal paper trays, Thermal video printer front panel etc. These are just places I have seen them recently. They are actually pretty clever but magnets are often used as an alternative these days.
Fraser