I got this little silver coin from German States and i would appreciate some help with grading and possible valuation.
Here are the pictures:


Oh, does anyone knows how to remove this ugly yellow stuff without causing any demage to the coin?
Also, there are two different km# for this coin, km#290 and km#297. The difference i noticed in between them is that the 6 looks bold and she shield seems shorter on km#297. Are there any other differences? Mine looks like km#290 but i didn't find record in catalogs about km#290 being minted in 1833, even though Numista says otherwise.
Sorry for all the question and thank you all for the help.
Paulo.