The movement from ebay was not a genuine tudor 2784, it was a regular 2783 with a tudor rotor.
http://cgi.ebay.com.hk/RARE-TUDOR-SUBMARINER-SNOWFLAKE-2784-RED-DATE-MOVEMENT-/200528520947?pt=LH_DefaultDomain_0&hash=item2eb06e66f3
Eta 2784 costs $50, tudor rotor from yuki $28.
A genuine Tudor 2784 costs alot more but there is no difference between them except for the decoration.