1988
1957
Impossible to answer as asked.
rc46661
You will need to call Browning.
1912 to 1936
1970
You follow the MFG recommendations, if they are not followed and you don't have a receipt that is was done then the MFG could void your warranty.
100-1000 or more depending on EXACTLY what you have.
Not enough information to even begin to hazard a guess.
1951
You forgot the serial number.
50-500 usd