If it's as it appears, with a blued hammer and trigger, then it's a pretty sure bet the entire gun has been reblued. Not uncommon that the barrel and cylinder took the bluing a bit differently than the frame. Plus, the sideplate doesn't look well-fit to the frame any longer. A pretty careful refinish, but that's what it looks like to me.

I'd think 1981 based on the serial. Nice gun really. I've been on the hunt for a pinned long barrel 48 in nice shape for some time. I'm not the only one as numerous Gunbroker auctions can attest.

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