You have to think of the usefulness. Mostly catalog numbers are used to either search here which standardizing a search format makes it much easier on the end user, or to search the internet/sites to purchase the album who normally insert this type of a standard anyways.
The loss of fidelity as you say which I assume means sticking exactly to what is on the album can be offset by putting the original catalog numbering in the notes category. That way all is kept, searching is easier, etc. I guess an extra bar at catalog could be added for original catalog numbers and standardized format.