Photo of Ruins, how to Paint it as if it is in original Time period I found this breath-taking photograph.

It is photograph of ruins of haveli (big house, mansion), in Northern India, built pre-1947 (before India split into India and Pakistan).

Hasn't been lived in since 1947, and architecture like this is no longer built (not that I know of, at least)

Luckily we live in digital age where people post all sorts of photos from around the world

I wish to paint a photo of this as if the haveli is in it's original, pristine condition, without modern technology, i.e. see those power lines on the top left.

As if I took a time machine to early 1940s Northern India, sat in front of this haveli, and started painting this with my oil pastels.

Any ideas how to do this?
I can tell you with certainty that architecture like this does exist, is still being built and is pretty common in Europe, for example in Halle or Leipzig, Germany. You can also see examples of it in Normandy (France). 

The technique of mortaring brick and coating it with cement or mud is pretty common. I imagine the biggest problem you will have is finding out the color used at the time. In order to keep buildings cool, the southern walls would usually have a light color - as white (a so-called lime wash) was easy to produce - I would go for that, unless someone with more experience in Indian architecture can add their knowledge...