If you are 'reasonably familiar with the London Underground' then you will know the giant hoops that any and all intending film makers have to jump through to be able to produce things on the network.
Yeah, no. The average Londoner who's familiar enough with the system to say "that's the wrong train" is not familiar with the business/logistics of filming on the Underground. I'm specifically talking about non-enthusiasts who noticed the problems.
There are very strict rules and regulations that have to be followed, and for many scenes the only way of filming them is to use one of two areas on the network - Charing Cross (disused) or Aldwych (disused).
I'm fully aware of the fact that there only two disused-but-available-for-filming stations on the network. The typical TV viewer/moviegoer is not. Besides, calling these "the only way of filming" is disingenuous. I've seen plenty of TV shows (fewer movies) filmed at "ordinary" stations (Maybe filmed during the night? I'm not sure how the legalities of having "bystanders" in your recording work.) When filming takes place on National Rail infrastructure this seems to be the preferred method...
with Sherlock it's the best that could be done
Well, apart from setting the story on the Jubilee line... That really wouldn't have altered much, especially if, as you say, they built their own carriage mockup rather than using actual withdrawn D78 stock (Did they not even use real seating/fittings/etc? The filming timeline matches up very well with the first few batches of stock withdrawal.).
As for your film depicting a 1972 stock train in 1971... again, what's the alternative? At the time of that film being shot the 1938 stock unit was out of commission undergoing a heavy overhaul at Acton Works.
Thanks for the extra information that's not available to the general public there... That explains why the 1938 stock wasn't used. As I previously said, using the 1972 stock to represent 1959/1962 stock is not at all unreasonable and the unpainted aluminium finish and slightly worse-for-wear interior probably matches the film's aesthetic better than LT Red and an immaculately preserved interior. I pointed it out as a fairly obvious "mistake" in a film that's otherwise very historically accurate. You (and others) seem to be misunderstanding me; I'm
not "attacking" filmmakers or the Underground in this case, I'm simply saying that even in a film that obviously went "above-and-beyond" to get things right (which I respect immensely) it still proved impossible/impractical to make everything perfect. Unfortunately, when you're striving for accuracy it often makes the few inaccurate details stand out more.
the costs of firstly transferring the 1972 stock unit off the branch and then getting the 1938 stock onto the branch are not insignificant
Of course not, but it's been done for far briefer appearances than the fairly extensive tube scenes that appeared in "The Bank Job". Again, I suspect that the use of 1972 stock was not entirely based on cost; see above for why an immaculately preserved 1938 train may not have been the best thing for the film.
As you've stated, you're doing nothing more than 'guessing', and clutching at straws...
Yes, absolutely. I made that abundantly clear, as you've obviously noticed. Congratulations on your English comprehension...
...maybe go and research just how much of a challenge some of this stuff is.
As I obviously don't have access to the same level of "insider information" you do (which is quite interesting; thanks! it's a shame you had to present it in such a confrontational manner), I apologise for the fact that my best guesses and personal observations don't match up with such industry secrets...