I took the seat belt receivers off of the w123 and w126 passenger seats to compare. It looks like the w126 seat only works with the w126 bracket, but I can swap over the buckle receiver itself by unbolting it from the bracket. I don't want to cut the wire, so I have to fish the wire out and feed the new one in. Not a huge problem. Every project has a snag, this one's relatively simple.

I was waiting to get the passenger seat installed to take pics - I thought it would look goofy with the fronts mismatched. I'll take pics when I'm all done.

I didn't measure the rails/tracks' height difference on the w123 vs w126 seats to see if the height difference is in the rails or the seat, but charmalu answered that question.

Since the height adjustment is rarely used on w123s, they tend to seize over time. Just try holding the side lever up and rock your weight back and forth. If that doesn't work, you can try some spray lube in the rails (beware, this can/will get messy).

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'82 300TD
'77 6.9
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'74 280
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