Some people will pay a premium for "Liberty Guns". Others don't see it as any different from a 1975 or a 1977 - it's just a forty-year-old gun.
If you had two identical condition guns, for the same price, and one was a Liberty Gun, I'd buy it, 'cause Liberty Guns are kinda cool. But if you were charging more for the Liberty Gun, I'd buy the cheaper one.