Metal objects, early Kurgan period: copper awls plus tanged, leaf-shaped copper knives or small daggers. Late Kurgan period: daggers, awls, flat shaft-hole axes. The Kurgan people of the northwest Caucasus mountain region (a center for metallurgy from way WAY back) at about 3500 BC and afterward possessed gold and silver vases, beads, and rings; also bull, goat and lion figurines; also copper axes, adzes, daggers and knives. No bronze objects were found; this means they either had no knowledge of alloying, or no access to tin. The last is unlikely; tin was available to the Persians and Greeks in later days, though the sites of the ancient tin mines are not now known; the major known site was in England, of course. The Kurgans would have panned their gold from rivers in the Caucasus mountains: gold, copper and silver can be found raw in their pure form, ready for use.
The lion figurines at first sound odd; there are certainly no lions in Europe or Asia today. But the Greeks also left artwork depicting lions, and wrote of wild lions in the mountains of Macedonia and Asia Minor, which came down into settled lands and preyed upon livestock. So the Kurgan artisans in the Caucasus mountains, north of Asia Minor, were probably also familiar with lions. Equally, there were wild bison in Latvia and Russia right up to modern times.
A note: the early Russian naturalist P. S. Pallas ("The Southern Provinces of the Russian Empire", originally published 1812) remarks that in the steppes of the lower Volga lived a giant land reptile called the Coluber Jaculator lizard, which the Russians named the courageous Sheltopufik; he wrote that it "is not venomous, is often six feet long; it moves about with erect head and breast, and when pursued defends itself by darting against the horse and his rider. There are likewise two other species of reptiles, the Berus, and the Halys, both of a poisonous nature." Large lizards like those of the species mentioned by Pallas inhabited the fringe lands of Asia from the Russian steppe all the way to the Persian Gulf. It is probably not a coincidence that the earliest dragon legends come from the same place!