On The Subject Of Altered Coins

Greetings classic coin buffs , I've had occasion to ponder the many ways scams are tried both on ebay and various forums.We've all seen the threads and articles for sale.
Also noteably we learned how easy it is to fake toning , this to me could possibly cover up many sins.

I remember reading in depth how some people are able to actually add a D mintmark to a 1916 dime,its been done.
This set me thinking , if a mint mark can be added , how easy would it be to remove one ? Logic tells me it would be easier than adding one.
Applying a nice dark tone to the coin takes minutes and would indeed help mask any alterations.

In theory at least I could do the above and render myself a very valuable coin couldnt I ?
I could even show it around to see if it passes muster with experts , id need to be careful to only show the revere though as showing the obverse might hinder upcoming auctions..ie..it might be recoqnised..just thinking is all..any flaws in that possibility?

Perhaps something to watch out for.