On the web page of Hublot it is possible to download a pdf file where it is explained how to detect a rep of the Big Bang model. Follows some pictures taken from this document.
As seen, following Hublot, we have to check three things:
a) Absence of regulator. Well, now this is not true, as the versions running at 21600 have a regulator (not functional). If we buy a version running at 28800 (BTW I think they are a better option) there will be no regulator. However, I explained here how to add a regulator:
http://www.rwg.cc/members/index.php?showtopic=74855
b and c) There are two versions of rotors in the rep market. One, with good ball bearing, but using sticks on the rotor mass. And another version with saw-like ball bearing but with engraved rotor. No version is perfect, so modding has to be made. About modding the H… I am working on that.
Some examples of reps:
The watch I bought, rotor engraved, bad ball bearing. There is no H under the rotor.
And follows one example with good bearing, but with stickers (and of bad quality). In addition, the screws never can be blue! They only can be black of with no colour (silver).
Therefore, modding on the rotor has to be made. In my opinion, the best option is to buy a rep with engraved rotor and modifying the ball bearing. After that, adding an H (future tuto) and adding a regulator, will produce a very good rep of this watch.
Needed Materials
As a minimum, you have to buy the ball bearing of the ETA/Valjoux 7750 and the external bolt. Follow the prices of these two parts and the references for Cousins web store:
VAL77501497 Valjoux 7750 1497 Ball Bearing