We've a set of patio doors, with three hinges per door, in white. Each
hinge comprises the mechanical hinge part, and a steel clip-on cap,
painted white.

Here's an example of a "good" one:-

http://summat.co.uk/DSC_0027.jpg


Now, the problem is that on one of them the clip-on cover has rusted
through, quite badly:-

http://summat.co.uk/DSC_0024.jpg

http://summat.co.uk/DSC_0025.jpg

Removing the cover, the hinge itself looks fine, apart from a bit of
staining from the cover, but I'm not worried about that:-

http://summat.co.uk/DSC_0026.jpg

So, my question(s)...

Can anyone identify the hinge type / manufacturer, so that I can either
buy the whole hinge and replace the cap from the new one, or try to
source a replacement cap. Does anyone know of a supplier that is likely
to provide spares?

As always, any help from the knowledgables always welcome.