I've been looking for instructions/manual for this enlarger. Does anyone know of a source (preferably UK)?

The questions I have are what is the removable panel for in the front of the head above the condenser?

Is the drawer in the side of the head, below the bulb and above the condenser, for contrast filters?

What is the red scale with the sliding door below the neg carrier in the front of the head for?

How does the auto-focus work? (I know it is a system for holding focus while raising or lowering the head, but how does it work?)