Only tiny differences.
The ones that leak are identical to the new ones but for one minute difference - the older light secures by way of 3 bolting points.
On the new light, it is identical except that one of the mounting points has been covered by a blanking sticker & no longer used (so the light is held by just 2 screw points).
I'm assuming that this screw point was discovered to be the point of entry for moisture.
I replaced mine a few months back for the new ones & had a good check over them side by side - everything appears exactly the same except for this.
Matt