The outer case of the later type fusebox is not deep enough to house the fuseboard from the earlier type of fusebox, this is what i tried to explain in my last post but having read that post back to myself i realise i made it a bit longwinded so it probably didnt make much sense lol!
There is 1 row of relays on the earlier fuseboard which sit higher than the rest of the relays and fuses meaning the earlier fusebox has to be deeper to allow for this, however on the later type fuseboard all the relays and fuses sit at the same height meaning the later box doesnt need the extra depth.
I have removed the earlier outer casing from my loom and fed the entire loom through the hole of the later outer casing (so as i wouldnt need to cut and re-join it) and tried to fit the earlier fuseboard into it but the fuseboard will not sit low enough to allow the lid to be put on due to the height of the relays.
The only thing i can think is that maybe there was different versions of the later type of fusebox, i removed this one from a J plate 5 door hatchback sierra think it was a 2.0 LX or something.