My post was half jest, however the point kind of stands.
At the end of the day on that list you have a 321, a 313, a 150, a 442, some Mk4s. Any kid who goes to the NRM and looks at those will say Wow a carriage, oh another, and another, and another, and another...
They also have to avoid having too many similar locos. They also need more things you can look at. Cut a 43 in half length ways, show them engineering.
The 91 is a good choice, i couldnt care less which one it is to be honest, as will a lot of people, allow them up close and I think a 92 would be a good option as well.
The NRM doesnt really have the space and need to become a linear scrap yard. Send the stuff that still works to a heritage line.