Yeah, those jeweled parts are awful looking, aren't they? No 'counting for taste, I guess. I bought a 586 a few years ago with the same parts jeweled, and replacing them was the first order of business. To the best of my knowledge, the parts are still available (they'd be different for your N-frame pre-27, of course) from S&W but they would likely be MIM, and therefore inappropriate for a pre-27, though admittedly they'd at least look better.
The grips appear to be typical S&W smooth target stocks and may or may not be original to the gun. I'm guessing probably not, but that's less of an issue in terms of value than the jeweled parts - if you could find some original parts for the replacement it would increase the value of the gun considerably. They'd need to be installed and fitted by a gunsmith, but that shouldn't be a big expense. I don't know if it's possible to have your parts re-case hardened. There are some specialty gunsmiths who do that type of work, but I'm not sure if they'd take the job or how much it would cost.