>>Nope.  My Westy doesn't have even one.
>
>Out of curiosity, does it have the P/S one?

Nope.

>>Are these available?  Is it worth trying to fix?
>
>...are you having stalling problems when the A/C compressor starts,
>or is it the aesthetics of the thing you care about?

Yes, it dies pretty reliably from idle if the A/C is on.

>One compromise  would be to add a wire and a diode like a 1N4004* to
>the P/S valve, so that either the steering pump or the A/C clutch
>could activate it.

I wondered about that.  A couple of diodes would be cheaper and more
reliable than a second valve and a T hose.