Sword

Try balancing the coin on your forefinger and then tap with another coin to hear how it sounds. Silver sounds very differently than base metal.

If the coin is not high grade and is very dirty, then cleaning it is OK. But you need to be very careful with high grade examples. For high grades, dabbing with a cotton bud soaked in acetone should be fine, but don't rub, as this will cause hairlines.

https://new.coinsweekly.com/people-and-markets/the-worlds-smallest-coin/#:~:text=The 1-kuna Hum coin,as the world's smallest coin.&text=The representative of Guinness World,Photo%3A Croatian Mint. The smallest "coin" is just 1.9mm. But I am not sure modern gimmicks count.

The issue next to the ear looks like a flan lamination flaw: a layer on the surface on the coin has flaked off.

Note the broken B in "BRITT". This is due to a broken punch or blocked die and is not a true error. However, some people would call it the RRITT error and they really shouldn't. You can make out the letters WWP next to HONI on the reverse. WWP are the initials of the master of the mint, William Wesley Pole. There is the letter W by the letter N of PENSE for Thomas Wyon the Younger, the chief engraver. I don't have a 1817 shilling, but have brought a nice sixpence of the same design some time ago.

Some of those chop marks are definitely Chinese characters. These circulated widely in China alongside other foreign silver dollars. 8 Reales is still on my list of things to get. Great history! I wasn't aware of that. I think the original ones are still very affordable if one is not gunning for a top grade example.

I don't think there is any problem with washing really dirty low grade coins gently if necessary.

I don't think the colour is "artificial". I think that perhaps someone has tried to clean it in the past (look in particular to the area in front of the horse). The tarnish is more easily removed from the worn areas of the coin and hence the appearance after "cleaning".

R7 rarity for someone good?

Low eye appeal but high grade hammered in slabs is not such a bad thing. Let investors buy these and leaving the well struck VF for collectors 😀.

This coin highlights that the criteria for grading milled coins are not sufficient (or appropriate) for "grading" hammered coins. One can assume that milled coins generally have decent round full weight flans and much less weakness or flat areas. Then one can concentrate on assessing the wear as it is the dominant factor in grading milled. Lustre + hairlines, etc are other complementary factors. But for hammered, the wear is not the single dominant factor and is often not even the most important factor. The grading done by TPG on hammered coins often seem to ignore flat areas (can be much more important than wear) and shape of flan. Hence, I find grading numbers rather meaningless for hammered.

Good! I seen your eBay listing and the photos you have there show off the lustre much better.

I love the designs of thalers. The quality of striking is often so much better than the English crowns of the same age. I like your 1604 Saxony thaler!

Didn't you say it's a keeper just 2 hours ago?

I would say it is around EF. (The coin looks dull but that could be due to photograph). If there is some lustre on the surfaces, perhaps worth about £35 or £40.