I noted that you said this BLR is 51 years old, but production of the BLR only began in 1969, so you may be a bit out on it's age. Those early Brownings were great rifles, regardless, so enjoy. Eagleye.
BLR Date Historic Information Serial Number Info
Made in Belgium from 1969 - 1972. Made in Japan from 1973 to present.
1976-1997 In 1975 Browning standardized its serial number identification which it followed until 1998. The Model 81 BLR was introduced in 1981. The Lightning BLR was introduced in 1995.
1. Serial Number
beginning with 01001
at the start of each year.
2. Date of Manufacture
is a two digit code Z=1
Y=2
X=3
W=4
V=5
T=6
R=7
P=8
N=9
M=0
3. BLR Type 127=BLR Lever Action
327=Model 81 BLR Long Action
227=Model 81 BLR Short Action
427=Lightning BLR