Potentiometers on front left panel (5274)
VR3 ???
VR7 ???
VR9 ???
Potentiometers on front right panel (5273)
VR4 Controls "video art" "picture effector"
VR5 Horizontal stretch (?)
VR6 Controls wipe stretch (horizontal and vertical)
VR7 Vertical stretch
VR8 Cor square
VR10 Vert scale for square
VR11 Vert scale (for diamond only?)
VR12 Horiz scale (for diamond only?)
VR13 Horiz skew (for diamond only?)
VR14 Vert skew (for diamond only?)
VR15 Bottom stretch (for diamond only?)
VR16 Angle for / diagonal wipe
VR17 Angle for \ diagonal wipe
VR18 Controls wipe horizontal position (even for wipes that can't be moved)
VR21 Controls wipe vertical positions (even for wipes that can't be moved)