i understand what your saying 'G' but i compared the 2 side by side, both exactly the same length, both exactly the same shape, and the bit that bolts to the hub came with a 17mm nut on the new one but manages to reuse the original nut off the old ones. the new track rod ends are made by a company called first line first line. iv used first line part before and they are of good quality, and i trust the motor factors where i get my parts from, iv used them since i started working on my own cars and thats over 10 years now.
and be right now... who is going to pay £53 for 1 track rod end for a 11-13 year old car? unless you took your car to Mercedes for the MOT and it failed on the track rod end.
i always say, check to see what the price is from the dealer and then have a look else where. in most cases dealer parts will work out cheaper overall. NEVER automatically assume that dealer parts will be over prices.