Removing cement render

[travis]

I am about to purchase a small granite stone cottage which has been rendered with cement. I would like to remove the render on one wall to reveal the stonework beneath. I have seen 'needle point scalers' in toolshops and wondered 1) if that is a suitable tool for a large area and 2) what sort of finish it leaves. I get the impression it would leave a surface more suitable for re-rendering that a restored stone look.
Any comments?
Thanks

 

[noseall]

it begs the question, why was it rendered in the first place?

 

[travis]

The house is actually in Portugal and the style of houses in the area are all typical rendered whitewashed walls. The point is, an extension has been added and what was an external wall is now an internal wall and I would like to reveal the original stone in the extension.
All I want to know is the best way to achieve that to leave a decent finish.
I accept that what is underneath may not be worth revealing but judging by the build of an adjoining ruin I think that is unlikely.

 

[noseall]

shot or sand blasting? after the bulky render has been removed of course.