In his book History of civilizations of Central Asia, Ahmad Hasan Dani writes that by mid-third millennium BC, there were copper, lead and gold ore sources near the Kavir desert.

http://tinyurl.com/cf5tms

Also, I am intrigued by the chamakam chant from Krishna Yajur Veda.
Esp. the 5th canto:
“…Gold is with me, Steel is with me, Lead is with me, Zinc is with me, Black iron is with me, Other metals like copper are with me…”

If Yajur veda was composed somewhere in 3rd millennium or late 2nd mill. BCE, then its interesting to note that not just bronze but many other metals and alloys and even steel were known to us.

Does this tally with what history says (like Mehrgarh and harappa excavations) regd. early 3rd or late 2nd millennium India?

Please have a look when you have a moment

Archaeology, for example, has revealed information about Iron age in India, the types of materials used in pottery etc. It may not be exactly in the same location where the Vedic events happened, but you could extrapolate the general development from archaeology around the region – for example, what we found in Mehrgarh dating to 7000 BCE and Harappa in 2500 BCE. This, I would say, provides an idea of the culture and their way of living. I don’t mind alternate dates at all, so long as they all fit together with such data as well.

Also, as I had said earlier, vedic civilisation had neither monuments nor artefacts that can be well preserved. The only thing they did want to preserve however, were the Vedas and they did succeed in that atleast partially. So Archaelogy may not help us in this context.