Leaky heater in Mk2. Is this a dashboard out job or can it all be done from the scuttle tray

Yes, from scuttle tray.

 

Clips on the fan housing slide to outer edges left and right.

I can't remember whether I  had to unclip the heater unit cold/hot cable at valve on heater.

 

Flush the system if you are fully draining it rather than clamping hoses..

Great- thanks mate. It's recently been flushed so I shall clamp

Looks like i'm doing this job this year, do you have to remove the whole fan/matrix unit completely or will the matrix slide out sideways? Do you have to split the fan box in half?

Might be different on a RHD car. I could not slide it out sideways because the wiper motor is in the way for me.

Hose clamps or a joining pipe. Slide 2 clips, heater resistor connection, I can't remember whether I released the cable attached to the inlet valve.

Exploded diagram

27 is the clip (one of them)

3 is fan speed resistor