Rain shields: Which way round to they mount?

[jagwit]

Do they mount with the bulk of the shield towards the centre of the V, or towards the outside of the car?

What is their main purpose?

[Whitact]

The bulk of the width is toward the centre. The mountings changed on the later cars and I think some replacements are drilled for either type. However, the JW restoration book shows the engine (rebuilt by Jaguar!) with them the other way round. But I think they would foul the bonnet in that configuration.
I believe they were just to deflect any water that came in through the louvres but I imagine they don't make a lot of difference. The FI conversions seem to run well without the shields.
Cheers,

[jagwit]

But I think they would foul the bonnet in that configuration.

They do.

Seems to me they are a feeble attempt to keep water away from the plugs in the V.