I have a lot of coins like this. Depending on the condition of the
reverse this coin is likely to far gone to identify. This coin is
still valuable to new people like us, as a source of experience. Soak this coin and brush it with a stiff nylon brush and pay attention to what is left on the coin. A nylon brush will likely remove some of the
patina... pay attention to the
patina that was removed and make note of what it looked like before the brushing removed it. Then use a SBBB on it, pay attention to the effect various amounts of pressure has on it... it'll remove some more
patina. Make note of the parts of the coin the SBBB removed and what they looked like beforehand. Probe what is left with a
dental pick while paying attention to how much pressure you can apply to parts of the coin without damaging it... then apply more pressure and damage the coin. Do it under magnification and pay attention to how different areas looks when scraped with the
dental pick. Make sure to pay attention to what that looks and feels like. Expose the core underneath the
patina and see if that actually has more detail than the
patina showed. Sometimes the core has alot of detail and you'll end up with a surprisingly detailed coin. All this will give you a basis to estimate what a coin can and cannot take. Also very importantly, it'll teach you what messing up looks like so you can tell when you've started over cleaning.