Check out GAHH. They are the source I'd use for interior/upholstery.

https://gahh.com/brand/mercedes?models_fit=1299&years=4889

As for body seals, you'll have various brands and sources to get these from. I'd only be cautious about Uro, they have had some issues in the past, but we also have a sales rep who frequents this forum.

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I recondition w123/w126/w124/w140/r107/r129/ steering boxes!


1984 300D "Elsa" odo reset 6/2011 147k
1983 300TD "Mitzi" ~268k OM603 powered
1995 E300 "Adelheid" 262k [Sold]