I have two adapter boards for Linhof Kardan. Outside dimensions are 162mm square.

Photos: http://picasaweb.google.com/10413151...Ovx-qDs7PKRuAE

The first two photos are for the 4x5 Technika board , the next two are for the 5x7 Technika board. Each adapter is 7,200 JPY (~87 USD), including worldwide EMS shipping.

Thanks for looking,
Kumar