If the finish is nice (it appears to be, but pictures can LIE!
) I would also leave it as is. Obviously, you can end up with something that looks far worse when trying to remove it. But that's just me not wishing to wreck a gun by using the wrong method, others (with experience!) may disagree.
I would love a six-inch K-frame magnum, there's kind of a hole in my cache for exactly that. I have three six-inch K-frames, but two are Fourth Change Hand Ejectors and the other is a 17-6. I'm pretty much needing a 15, 19 or 66, six-inch.
Nobody has guessed at the price you paid yet. I would say, in my opinion, with the market in my area, that you would have done a FINE job if you managed to bring that home for $500 out of pocket, out the door. At $600, it is -not- a bad buy, as long as it's 100% functional and the timing is terrific and it locks up tight. Higher than that and it starts to sound a bit pricey for my tastes. If you walked away for any money UNDER $500, you really got a super buy.
Pinned & recessed ceased around 1982.