MCPro: M/S/L LEDS & joystick functions?

[niekbeem]

I own a 2nd hand v1 MC Pro with 4 faders which does outstanding duty in my projectstudio, though; I never understood the functionality of some LEDS and buttons:

On a MC Pro with 4 faders:
What do the LEDS M , S and L left-below the 4 faders mean?
I found out that the L lights when I somehow link or group faders, so it must be some LINK-identification?

On a MC Pro with 2 joysticks:
How do the buttons VIEW and SHUTTLE work?
How does the LINK-button work?

Thanks in advance for any explanation.
Niek/ Amsterdam.