A lot of surplus stores collect and refurbish computers and should have plenty of excess parts that end up tossed or in a parts bin. I'd be willing to bet you can get plenty of spare keys. I guess it mostly depends on what style of bracket it has. Any key would work and a little paint or nail polish to remind you that the 'e' is on top and the 'v' is on the bottom row.

Likewise, as mentioned, the manufacturer can probably also send you some new keys to install... though my way is cheaper. Good luck annie,