I'm looking at buying a SP1 with a s/n of SP542XX.  Seller believes made in 1976.  Can anyone confirm that? Looked at the s/n page here and found info below.  Are the numbers read as SP55301 AND BELOW or do they start there?  THANKS.

Colt 800-962-COLT
CC001616 and Below - Pre-Ban
CH019500 and Below - Pre-Ban
GC018500 and Below - Pre-Ban
LH011326 and Below - Pre-Ban
MH086020 and Below - Pre-Ban
NL004800 and Below - Pre-Ban
SL027246 and Below - Pre-Ban
SP360200 and Below - Pre-Ban
1963 SP00001-SP00023**
1964 SP00101
1965 SP02501
1966 SP05600
1967 SP08250
1968 SP10750
1969 SP14000-SP14653
1970 SP15001-SP15473
1971 SP16001
1972 SP19401
1973 SP24201
1974 SP32601
1975 SP43801
1976 SP55301
1977 SP67651
1978 SP83400
ST038100 and Below - Pre-Ban
TA10100 and Below - Pre-Ban
BD000134 and Below - Pre-Ban (AR-15A3 Tactical Carbine - very rare model)
MT00001 and Above - Post-Ban
BK000001and Above - Post Ban (CAR-A3)
CST000001 and Above - Post-Ban (Began Late 1997 Production)
CMH000001 and Above - Post Ban
CCH010000 and Above - Post Ban MT6700, MT6700C and MT6700CH series, 1998 production

Actualy that serial numbers start at the corresponding year alongside. Making that weapon a 1975 vintage.

I always thought the serial # on my SP-1 was sort of odd when trying to figure year of manufacture. Serial # is SP149XXX?  Any idea of year made? I bought it new in 1981. $389!!!!