I agree with the grade of VF-20. If the reverse were a little better it might have made it to 25.
The toning displayed on this half is very common, and as has been mentioned, indicative of an old cleaning. Often, however, if this were submitted to a
TPG I've seen a lot of these go through (not with NGC) without a details for cleaning.
A collector will either enjoy the toning, or hate it, and there probably isn't a lot of in-between. I like this coin.