If I'd know they were that cheap, I'da bought new ones.
Mine have a vacuum switch in them to lock the seat backs when the engine is running and the doors are closed and I had to bust them open to make them work. What a PITA.

Michael

__________________
Usta haves '69 250/8, '76 280C, 1971 250C 114.023, 1976 450SEL 116.033
Current have, 1983 300SD 126.120