To change the viewpoint (move, raise or lower the seat height) in the B707, please, try using the following keys:

[SHIFT+ENTER] -----> UPWARD

[SHIFT+BACKSPACE] -----> DOWNWARD

[CTRL+ENTER] -----> BACKWARD

[CRTL+BACKSPACE] -----> FORWARD

[SHIFT+ARROWS] -----> TO SEE AROUND

Hope this helps,

Pinatubo.