What are these V-shaped metal bits on my vintage brake callipers?

On each side of my 70's Universal Mod 125's there's a large rubber-covered v-shaped, bent piece of metal between the pad and the callipers as shown. What is it, what does it do and is it part of the adjustment process?

Potentially related, do these callipers take the usual type of pads you'd see on a modern road bike? I note that they are visually quite different.

http://dl.dropboxusercontent.com/u/2633837/liberati/calipers.jpg

Thanks as always

They're wheel guides, for super-fast wheel changes. Always seemed a bit redundant to me.

Yes, you can fit modern shoes: something like these mean you can just replace the pads as they wear out, rather than having to buy the whole assembly each time.

are they not to help set cable tension? thats what i have always used them for as you can hold the caliper together with the pads just off the rim with one hand then tighten the nut with for the cable with the other.

Probably more useful in that regard, than their intended purpose!

are they not to help set cable tension? thats what i have always used them for as you can hold the caliper together with the pads just off the rim with one hand then tighten the nut with for the cable with the other.

Ha! That's a really good idea :D

Thanks again, Scilly. Found them cheaper on Amazon, btw (£5). And free delivery if you have Prime :)

Probably more useful in that regard, than their intended purpose!

indeed they are definitely handy in that regard.
i can't say i have ever wished for a wheel guide on bike without them though.