Can I share some of my experience here? If you already know this then my apologies.
I was a bit of a coin collector extraordinaire in my younger days (8-21 yrs old) as my father is a serious collector. He carted me to so many coin shows and auctions as a kid - literally several per month. I couldn't help but learn, and we are talking US coins which have many more varieties and age.
What I learned is how to grade a coin. The luster of a coin is secondary to the wear points on the design of the coin when grading a piece.
For example, take a look at the diamond pattern on King George's crown in the picture below:
https://www.prospectingaustralia.com/forum/img/member-images/1695/1420971284_img_20150111_204539.jpg
This is one of the high points of the design when minted, and the first area to show wear on the coin. Notice diamond two and three are not clear and show some wear. So even if the coin had no scratches and otherwise looks beautiful, a dealer can see it is not a uncirculated coin, and the wear dictates the grade of the coin, and ultimately the price. Also the tiny nick on the rim.
Not claiming to being an expert in Australian coins - I would give the the Florin a grade of Extra Fine MS50 from the pictures supplied. The price difference between Extra Fine and Uncirculated is probably substantial.
Of course cleaning a coin if detectable also brings down the value - and dealers can tell by the colour of the luster or even residue left on the coin that can be seen with a powerful microscope/ loupe.
Both of these coins are in great condition, especially when you know where they came from, but I just wanted to highlight the way a coin is graded and what dictates the value.