Why not use a 'dip' switch? they are available in a single switch style. http://components.omron.com/components/web/pdflib.nsf/0/6EBABFA27C77F9908625730F0055AD35/$file/A6T_1110.pdf
A standard DIP switch won't fit (0.3" vs 0.1"). Those look like something Zippy or JAE might make. It's essentially a push-pull action SPST vertical slide switch. Are there any markings anywhere on the switch body?