Irrespective of what motivates your final decision, I just had the same seals replaced in the '87 SDL for $350 from my local mechanic in the Sacramento area.
'04 ML500 - 53k, Inspiration Edition, Desert Silver
'11 Audi A4 Avant - Brilliant Black
'87 300SDL sold
'99 C280 Sport sold
'85 190E 2.3 sold