A Browning over and under is worth about $1,000-1,500 on it own and the fact that it's a Belgium made Browing increases the price significanly. I would say somewhere in the range of $500 to $750 more. The belgium made Browning is the most collectible and popular.
Yes, Browning has made the Superposed Lightning in Belgium.
Yes
You jmust call Browning to find out.
1978
Under the barrel release lever on the top of the frame
40891 s5
100-1000 usd
Browning offers letters now for @ $40 USD
100-1000 usd
Browning offers history letters for @$40 USD
Go to Browning's site, click on Support then date your firearm.