The orange areas seems to me that it has been cleaned. And there is verdigris. Copper is not orange but it will look like that when it has been cleaned. With an old copper like this you want a more chocolate example. Yes, new copper will be shiny and bright (still not orange) but when old copper is cleaned you get this false color. Just my opinion.
You can look through the coins available to buy on e-bay and I can assure you there are hundreds for sale on there right now that are worse than this one. Ground coins have porosity normally and there is none of that going on here. I don't think the color will look like these pics in hand. Coin was less than $30 so I am not going to get hurt on it.
For less than 30 bucks, I think you did OK. As to @SensibleSal66 's nicer ones from "out of the ground", I'd like to see those. I have seen some pretty pristine large cents come out of the ground down here in SE GA, but seldom that smooth. Even the nice ones usually have some degree of porosity. Here is a really nice 1798 S-166 that a friend of mine dug down here. It's super nice, but you can see it does have a degree of granularity on the reverse.
That 1803 is certainly not better than the 1827 that the 1827 in the OP, in terms of surface preservation. The 1847 is indeed sharp in terms of details- but it does have the telltale granularity (porosity).
