I can see it under magnifying glass. But I dont think enough to warrant risking the coin. I know what it is and year. So thats good enough for me. My 2nd oldest coin.
Even I wouldn't touch that one, you can clearly see 1800, anything else would turn that baby into a blank disc. I agree with our other metal detecting brothers, great find. I'm crazy usually to keep doing things to get a date, but your good to go. Congrats!
If there's anything I've learned from large coppers..don't try to "improve" it. They only get worse.. The only one thing I will do sometimes it a very light olive oil treatment with a Q tip. As for your yours I'd put it in a plastic holder and love it for what it is. A beautiful piece of history.
The choice as whether to clean or not to clean is entirely up to you! However, there are 29 Varieties for the 1800 Large Cent, 18 for the Normal Date of which your's may be one. There is only 1 Very Common Normal Date Variety, 6 Scarce, 6 Very Scarce, 1 Rare, 3 Very Rare and 1 (I believe) Extremely Rare. From what I can see, it does not appear to be an Overdate Variety of which there are 4 for the 1800/1798 Overdate and 7 for the 1800/79 Overdate. However, a better close-up of the Date may help determine for sure.