Factory or not, it is very nice
As long as the engraving speaks to you and you feel the price was reasonable, there is nothing wrong with it. There are lots of your fellow Forum members that own guns that were not engraved by the Factory. Just do it, don't second guess yourself and don't ask everyone if you did OK. Be happy that it is a gun you can appreciate
BTW, look under the cylinder release for initials. That is a common hiding place
Many years ago I came across an engraver at the Tulsa show. He had two snubbies (686 & 624) on his table that he engraved in the same pattern. His price was great but I only had enough money on me for one. So I bought the 686 and promised to come back for the 624 the next day after I hit the ATMs.
Well I could not find him that next day, it is an 11 acre room after all. The point of the rambling is if you like it grab it.
If you wait for other folks to push you one way or the other, you could miss the deal altogether
I did not know it at the time, but mine was one of the first 2 1/2" 686s that were made as a Lew Horton Exclusive