This is an updated post:
I purchased these headphones after having damaged my old pair of Sennheiser headphones (and after trying the awful Sony MDR-570LP's).
The original pair of Senn's I purchased from HMV a couple of years ago now (for £16 no longer stocked), and they looked physically identical to the ones here. The only difference I could concern is the lack of a model number on the old ones I had.
But the new headphones arrived today and despite a side by side comparison and still only wear and the lack of a model number on my old ones being physically different, I tried them out together (I had to do this at a modest volume due to me damaging the old pair slightly).
These are not the same headphones.
The old pair had a sound quality I have never heard matched from a pair of headphones, the new ones have a distinct lack of range and the bass is heavier and muffled.
It seems the speakers used in this model are inferior to the old ones.
It seem you can't judge a book by its cover really works in the case :(
PS. The headphones I received had been opened and repackaged.