One for my improper use collection, and definitely one of the more colorful combinations of stamps. They apparently ran out of 1-cent documentaries (this was early in the tax period and on the west coast, so it’s plausible) and so put together proprietary battleships in an amount adding up to the missing cent (5/8c + 1/4c + 1/8c).

There isn’t any ready indication that this is contrived, in my opinion.