Barrel and receiver
Call Browning or check the serial number on their website if it is up.
Comparison to known serial numbers.
No
Impossible to value with only a serial number.
100-500 USD
By including the serial number in your question.
Most likely, yes.
The 'M' in the serial number indicates the gun is a BAR sporting rifle, but there was no M57 serialization since the gun was not introduced until 1967. Please check ther serial number.
1975
100-1000 usd
Check again, that's not a Winchester serial number.
Check the receiver and barrel.