Invalid or non-existent item ID.That's the alternator shield you're talking about. Designed to stop road dirt/mud and water covering the alternator.
The F version was made of a fibrous material that eventually degraded until it fell off.
The TF version is made of plastic and tends to last longer. Usually these disappear from being left off after work has been done in that area.
The TF version is available from Rimmer Brothers, or second hand from ebay.
I actually made one up by cutting up a large plastic container. It's pretty easy to shape to fit and drill appropriate fixing holes. It has been working effectively for 4 years now!
Cheap and effective!