The root of the issue lies in writing a mission statement and sticking with it through the progressive operators. If you are going to paint the tenders and cabs, either way, it needs to be written down and included as part of the foundation of the mission statement for present and future operators.
On top of that, another layer should be written that states a timeline for the weeks progressing up to a photo charter. You cannot weather a real engine overnight (Lerro did a pretty good job) and you can't do this stuff last minute because it just never works. Are you going to take spark screens off? If you are, you need to do some research to back up your arguments as to why it's safe to do so and what measures you intend to take, as well as document scientifically how the removal does not affect fire mitigation. (A hint, Andersson cyclone front ends work better without impeded draft.)
If these things aren't done, it will always be a let down for whatever patrons to charters find when they expect some authentic recreation, only to find mistakes and last minute botch jobs.