Futaba F14 Navy Switches

Help needed again please?
A pal has the above radio and wants to expand the available channels
He needs a Linear Proportional Channel, Part number F1601
And also  a 3 position switch Part  number F1600
I have tried to locate these two items,but apparently they are no longer made,and the stockists I have tried have none in stock.
Can anyone help or advise please.
They are for a very special model of the Japanese Battleship Yamato,which has loads of working items on it.
Thanks
Mick F

try here

http://www.westbourne-model.co.uk/ModelBoat/Robbe_F_Series_Radios.html


scroll almost half way for the 1601 and the 1600 is just below it