ADKM:

 

Yes I have been told that, but I need the the functionality it allows.

 

I cloned the SD card, but with it, the new Pi just shows a multi-coloured screen. Back to square 1.

 

Thats because you probably have not got the updates for the new pi to boot installed if you have never apt-get update or apt-get upgraded on it. I dont really bother doing that, the pis are just short term project things so I reflash the card on each thing I am doing.

You could try wifi or an old USB to ethernet device on the old pi and see if either connect. then do the updates. But back then the raspbian installs were really limited in what they had because the pi was a completely underpowered device, they had to be careful what they put into the images.

Otherwise see if you can borrow another old pi to update the card in and then try it in the new pi.

Confirm that the card is cloned ok by booting it in your old pi, just incase the partitions didnt all come across when you cloned it.