Now, I did buy a 686 one time that had been really butchered with a dremel. Your post reminds me of this.
I had looked at the pics and swear I never noticed this but someone had tried to sculpt the trigger guard edges, it didn't work. Ive used dremels enough to form an opinion on what happened and what they used to do it. When I say I e used dremels alot I do not mean on firearms, I haven't unless its with a soft buffing bob, that's it.
Well, this person had some sort of physical ailment that caused them to shake alot and to boot Id bet they had chucked up a hard aluminum oxide wheel for grinding metal. The seller said he had not actually looked at any of the guns he was selling, which prompted me to ask how he came up with the descriptions he had written. I don't remember getting an answer.
Im telling you, people can do alot with photoshop these days. He took it back, gave me a full refund with shipping and an apology. I couldn't be too mad after that but still, why???
Nothing wrong with yours though, no. If you got it off of gunbroker and have any plans to repeat this process please always remember to never forget, never buy any gun if they don't give you an inspection time frame and the ability to return it, and do your inspection BEFORE taking legal possession of the firearm. I have a kit I take with me with all of the tools I need to perform a pretty thorough inspection of a used revolver. I have recently added pin gauges, although throat sizes not being to my liking wouldn't constitute a basis for a return but Its something to weigh.
If you do plan to buy more used revolvers and want to know what to look at to determine the honest condition of it there is plenty of info here and elsewhere online on how to do an inspection and what tools are needed. I've even added a cheap (but actually very nice) borescope to check the bore and chambers and the 45°mirrors let you get a really good close up view of the top strap in the area where flame cutting occurs.
Again, enjoy your very nice 586 and shoot it often.