But if I were to hazard a guess, Belstaff is simply banking on average consumers not noticing that these differences exist. Consider how many details are important to make an Indy jacket (as an example) that is reasonably close to the original in ROTLA, and yet people off the street will readily identify almost any brown leather jacket worn with a generic fedora as an Indy costume.
Why is the original a great jacket?
1) Subdued but refined colour scheme, especially the red button hole that 'pops'.
2) Cuffs that are over-the-top enough to be original, yet still within the design aesthetics (big cuffs are okay with a big collar).
The new one simply looks like a step backwards...everything is more conservative except the collar. Once again, mixing aesthetics which weakens all.
Incidentally, the new jacket isn't done any favours by the photograph using a model that has a small head. You need a large 'crown' in order for this to work without wearing a hat. The photo also suffers from giving the impression that there's a reverse v-shape between shoulders and waist (the shoulders by design or illusion look slimmer than the waist...which is always a no-no in male fashion design).
The average person on the street, walking into the store, will be told that this is the Sherlock jacket. They'll buy it. Then they'll enthusiastically look up their purchase on the net to confirm what a great deal they got or find people who are also fans of the jacket. Then they'll stumble across FilmJackets, and learn that they made a mistake. It's not like it hasn't happened before...
Nihil tam incertum nec tam inaestimabile est quam animus multitudinis.
- Titus Livius