Hi, assuming the SEL is the same year (76 - 80) as the '79, the internals are similar, but the housing and wood panel is different. Also, the location of the various vacuum switches are different, but the actual parts are the same. You can remove the parts from either panel and interchange them.

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Richard Wooldridge
'01 ML320
'82 300D 4.3L V6/T700R4 conversion
'82 380SL, '86 560SL engine/trans. installed
'79 450SL, digital servo update
'75 280C