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Unsure where you got 1977 from. The serial number places it in the very early 1990s, likely 1990. This may be a rifle made for a Remington employee. First one I've seen marked so. This is either the assembler or inspector.
The woox reference guide I believe is AI produced junk. Run away from it and never look at it again. Its totally wrong on most aspects. The rifle you refer to is unique for one reason or another. Custom shop guns are NOT date coded. Employees could inspire how the end product looked. I wouldn't discount a 90s rifle if you like it. It would still be considered desirable by most.