Why don't you just swap the bases?

I.E., put the 92 seat on the 89 electric base. Only six fasteners to remove....

Jim

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14 E250 BlueTEC black. 45k miles
95 E320 Cabriolet Emerald green 66k miles
94 E320 Cabriolet Emerald green 152k miles
85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles

Didn't think about that at the time, but I came to that conclusion after realizing on the diagram that I just need to swap the controller out and the connections to the 5 motors are the same. I'll give that a try tonight, thanks!