Mk1 wiring to 2lt pinto - doing my head in.

Pinto's have a solenoid, it is mounted on the starter not remotely like it is on the Kent starter.  Wiring it is really no different.
I would suggest you get hold of a MK2 manual to help you sort out what is what by colour.
 
Yes you will need to 'extend' the alternator wiring to reach around to the opposite side of the engine. 

Hi Jim
If you have already un wound the loom, run one of the reds to the starter solenoid (this powers up the rest of the car loom), you still need battery cable from battery + to same large terminal on solenoid. Run slightly larger wire than the orignal 2 (relitive to how big the alty output is) from B+ alty terminal to either B+ terminal on battery or same terminal on solenoid (which will now be getting bulky) which ever is most convenient. Then cut or unjoin the orignal second red from the loom and insolate the cut or unjoin. you now have Battery positive down to the solenoid,Battery positive into the loom via the solenoid orignal red, Battery positive to the large alty terminal to recharge when the alty is running. Clear as muddy water. Give me a call if you need to un muddy.