Revilla: Your Low-Flying article was excellent & included ALL the necessary information & warnings required.
Superlight91: AFAIK these MFRU's are in short supply. Caterham are out of stock. Ebay could be your friend? As mine was 19 years old I decided to remove it completely & replace with individual relays. Procrastination stopped me doing this 11 years ago as once the starter relay was bypassed everything else worked. It was only when I was getting intermittent fuel problems that I decided to junk the MFRU (I don't have a lambda sensor).
At some point in the future I'd like to completely replace the engine loom, fuse, relay box. However whilst it still works.....................