I think G-06 is the underlying grade.
For certain, I wouldn't let a
TPG have a chance to call it a details coin. It
shouldn't be detailed, but it could be a pricey roll of the dice for the coin's value. IMHO it's a bourse floor G-06, but I would expect some price haggling because of the scratches. If I'm a seller here, I'm emphasizing the circulation cameo as a tradeoff for the scratches. I don't think the carbon spots on the neck or the stains (rust from iron contact? organic crud?) are an issue for the grade.
It's a pesky date in any grade, and there's a collector who wants to fill that hole. Just take the time until that collector comes along and don't undersell the coin. It's decent for the grade. Not all details coins are equal. I'd snag this one any day over a holed or bent coin or a whizzed or brillo pad special.