Those imported into the US with the Browning name (since 1956) have had varnished and later polyurethane stocks. Early guns with the FN markings had oil finish stocks.
100-10000 USD, who knows. You need a professional appraiser.
22LR
The Challenger II has an all steel frame and the Challenger III has an alloy frame; I don't know what the alloy is.
15
Browning's web site has a sn search function.
You will have to call Browning or visit their website and look up the sn to find out.
The Browning medalist was the best by far.If you can find one,these were made from 1959-1974.
50 - 400 usd
50-1000 usd
100-400
A 22lr semi-automatic pistol.
2-20 usd