You can use one from an Orion .. same parts.

It's one-piece . LHS A-Pillar plug to Control switch, then to RHS A-Pillar plug.
Make sure you have the connectors at the A-pillars, or you will need the two door jumpers (with rubber grommets/tubes) too. Trust me .. that one will connect to everything. I used Orion Ghia i parts for my van.

Damo is partly correct. We build cars now using many different variants .. They are built with different wiring with various features..... but we SERVICE with a reduced number ... as many as will allow features to be supported.
The new Focus has around 30 different wirings for drivers door! We service with about 10.

Mk 4 was done a bit different, using add-on wiring for most extra services such as Central-locking, Mirrors, etc

The reason I went to such lengths before is .. cos that is part of my job at Ford .. Wiring!