Actually, with all due respect to MBDoc, the retrofit for early (pre-94) 500Es were 500SL calipers, made out of iron...only european '92 & '93 500Es got the 320mm brakes (and an oil cooler) from the 600SL.
According to documentation I have, the 500E front hubs were swiped from the R129, so I'd think the calipers would bolt right up.
Lastly, I'd think the suspension upright would be a non-issue, as that would present a wheel clearance issue, which cannot be the case here.
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car