I like to think about it like this:
At the two ends of a coin's desirability, you have 'Mint State' ( made this morning)
'and where the hell has this been' ( on the beach for 100 years ).
Both these types would be expected to have an even patina or finish. In fact, not having an even finish would be unusual.
Now what if the coin had a few year's wear, so that the patina was different on the high spots, and this coin was then lost- fell down the back of a drawer, put in a box in the loft for years, etc etc.....yes, there is a chance that a new patina would develop that could cover up the differences in patination between the high and low spots. Perhaps, but these types of places for a coin to go are relatively benign - not really patina-forming.
There are places that a coin could sit for years and change its overall appearance, like when fallen under floorboards onto damp ground beneath,
or at the back of a drawer like as above, BUT - why would both sides look the same?
One side has been open to the 'elements' rather more than the other.....
When you see one coin like the one above, you have to take notice. This doesn't mean it's been played with.
However, when you suddenly see several pop up from the same type of sellers, with no older pictures of the coins available to compare with,
you have to start to wonder......the same is true of the multicoloured horrors that have strangely appeared for sale in the US amongst the less
well- known dealers.....:-)