UPDATE
Just proves knowledge is the most valuable tool in your box..!!!!
Got the hub stripped down in 5 minutes tonight
once I knew what I was dealing with....using the help from this forum ...
A little heat on the dust cover and it came straight off with some careful levering , then the LH threaded plug came out no problem too. Perhaps its just my lucky day!
Plus the dust cover is virtually undamaged (apart from the spot welds..!!)
Slightly weird design? I can't imagine anyone can get that cover off without breaking it apart, even back in the day when it was current.
Perhaps that's why the welds are so small?
Thinking about it the plugs are a little weird too, both being LH thread?
I'd expect one to be LH and the other RH to prevent rotation causing them to undo. But as they're both the same why not make them "normal" RH to avoid mistakes?
Anyway, perhaps that's thinking too deeply about it...!!
Thanks