Sir or Madam -- It looks valuable ... First:

DO NOT CLEAN YOUR COIN. CLEANING RUINS VALUE.

If it is genuine (I think it is), and not a copy, it is probably worth $1000 US dollars or substantially more.

You have a Lord Baltimore shilling made out of silver. There is a page on them here:

https://coinscatalog.net/usa/coin-silver-shilling-lord-baltimore-km-6-maryland-lord-baltimore

Your coin is in nice condition. That's why I think it is worth more than $1000. The one in my picture is in horrible condition, and it sold for $1467 US dollars during a 2017 auction.

My coin database also has an entry (without picture) for a counterfeit Lord Baltimore shilling. It sold for $30. So you see, you must determine if your coin is real or fake. The best way to do this is to send it (insured for $5000) to PCGS, NGC, or ICG. Look them up on the Internet. Contact them with your picture and ask for what they recommend.