You state the major problem with colorizing - that the 'mistakes in the color scheme' are falsifying the information being presented as a historic record and Mr. Boulware's "Truth". This is exactly why the use of colorizing is not an enhancement of nor an understanding of history. If the image was not in color it is a false history, not an enhanced one.
I don't agree either that 'color' is the pinnacle of photographic technology. Maybe it -is- digital photography. Maybe there is something even better coming next week. Great photographers that have had color available in the 20th century didn't always use it. This is still true today.
As to your example, look at the Durango Mc Donalds disappearing act that was posted. The image may look 'better' but it also looks 'weird'. I've done it to some of my own images too, erasing a 20th century artifact, and even though it looks different and arguably 'better' I wouldn't call my changed images any sort of historical record. The danger is when the image gets separated from the explanation, and is assumed as 'truth'. Who knows where an image will end up in 2090 and what will be derived from it? Will some historian assume the McD's was torn down in October of 2006 and rebuilt in November? What assumptions do we make now about the photographic railroad records in just the same manner?
As to your query, you can do any of your choices, so there really isn't a question, but there are ethical consequences. Advertising is full of illusion and 'created' realities. Movies are half digitally created to the point that we can't readily see the difference. In these realms the ethics are different than creating an historic record of an event. What we are looking at (I think) when we see images in the DPL are artifacts of the time and place that once was, and to screw around with them is really a travesty.
