Tried to download a livery earlier for 1972 LU stock, as far as I'm aware only the one route uses said rolling stock (with the possible exception of IOW route), but to download the livery I required a German route and the sand patch upgrade, what in all of the daily.mail f*ckwittery is that all about?
It's just an UI issue, I would assume. Bakerloo Line was a TSW2 core route, so the game shows all 3 TSW2 core routes as requirements. But I think it's just an UI bug and you should be able to download and use the LU stock livery just fine.
I remember downloading a 72 tube stock when cc first launched in tsw2 but I was not able to select it from the timetable screen even after it was downloaded. It apparently needed ecw or something else to run it when I clicked on required content. Obviosuly didn't test it out, but wasn't able to select the cc livery at all.