What is the value of the pots in the controller for Real Flight Classic made for game port version?

http://www.soldcentralfl.com/flyingpenguin/rcstick.htm

here's a howto on building your own box. the values for this setup is 150k, but it uses 1M ohm resistors. you need linear taper pots. the range the stick movement gives you is about 150k on a 1M pot.