Careful about the dial as well.
The Asian 21J comes with DW that's positioned more towards the centre compared to ETA2824 and Asian2824/36 clones. This means the DW window had to be cut in a different place to accomodate the DW position. So...in case you ever decide to upgrade the mov't from A21J to A2824 or 2836 clone, you'll need a new, diferent dial to fit.
I believe hand posts are also diferent dimensions, so beside a new dial you may need a new hand set to fit.
babola