Beautiful and well-struck King V fish scale!
Market acceptable contact marks can be a bit more forgiving on a fish scale than a larger coin. (Think of what they endured rubbing shoulders with heavier and larger twenty-five cent pieces in somebody's pocket!)
I see several minor contact marks on the obverse, in addition to the long contact mark. There are a few dings in the field at 3 o'clock and some surface abrasions below the portrait. The reverse has noticeable contact marks left of the date and right of the crown and a fairly deep mark beneath the date, as well as a few minor surface abrasions. On an UNC coin, these would be issues, but I don't see them as earning a details grade on an AU coin.
The obverse photo has some glare on King V's eyebrow, and wear in that spot can be a defining difference between AU-53 and AU-55. I see your coin at least as AU-53, and probably AU-55. There is plenty of original luster and the details are sharp enough for AU-55. The coin has great eye appeal.
It isn't worth submitting to a TPG
, but I don't think you would have much trouble finding a buyer at an AU price at a show. Again, it's a beautiful coin.