For what it is worth, I just went through the seat repair investigation process on my 124. There is an article in a past issur of the Star discussing redoing your seats - they concluded that it was better to let an upholstery shop do it if you want them to look right. Thus forewarned, I went to my local MB dealer - they recommended an upholstery shop that does all their interior work. The shop quoted me a $125 labor charge for doing either the pad, the spring frame, or both at the same time. The spring frame part was $92, and the pad was $86. They said that on most of the MB seats that they do springs and pads on with MB parts, the owners complain that the new springs are too hard and uncomfortable for the first year or so. They said since my seats weren't that bad off, to try Sheepskin covers and/or an external seat cushion before going to the expense of having them do the seats. Hope this helps.
87 300E, 62k miles