Correct, they are not in the parts manual.
Although there are not allot of original wartime good engine bay photos that I know of, this is one, and it shows the clips. It's either original, or perhaps mod...which I doubt.
There must be a good reason...
As the wire is separate anyway...otherwise I guess it would be in the main webbing like the oil pressure wire?
It is funny restorers in all those years misted it. As in below photo, again you clearly see the configuration. It's the original GP film surfaced on Ebay a few years ago.

Anyway, I wanted it...like a few others.
Btw, the 2 small rubbers bumpers on the hoof are also not in the manual....so that does not say everything, as they surely are on period wartime pictures.
Cheers, Jacco