Only half a cover, but a wholly commercial usage
The most recent addition to my collection of 14¢ American Indian stamps on cover is a cover fragment mailed from Ohio to Denmark in August 1932. The 14¢ postage covered the then recently-introduced 8¢ per ounce rate for air mail within the United States and surface mail to Europe, plus 3¢ per half ounce for air mail within Europe.
The cover was at some poit in the presumably distance past cut down to probably about half of its original size, probably to make it fit more nicely on an album page. I bought it because it’s a difficult solo usage that fits into my collection, but it’s definitely not the nicest example I own.
I can remember a stamp or two that I wish I had left alone, and perhaps you can think of a stamp or cover that you didn’t treat quite as well as you wish you had. Still, I would like to think that in today’s collecting world, a cover such as this would have been preserved intact as a piece of postal history. The visual impact of a full cover instead of a fragment like this is indisputable.