You sure this isn't an EJN 757 instead of a JEN 757? I have a EJN 757 in 3006 and would also be interested in any info. for this rifle.
You will need to supply a serial number to get a answer to your question.
1993
Hello Between Nov 1974 ( serial 900000) and sept 1976 ( serial 970000) Delcourt JP Belgium
Browning.com has sn data under customer service.
Browning Auto-5 manufactured in 1965 by FN of Belgium
10-400 usd
Probably 1966. Call Browning to verify. Can't value with just the serial number
If it was manufactured prior to 1968 it probably doesn't have one.
HI, the gun was manufactured in 1969, Carl
100-1000 or more depending on specifics
when was the savage model 99 serial number 655391 manufactured
A Colt Python serial number 35128e was manufactured about 1964