Anyone know if an '89 300E Idle Control Unit can be replaced by an '88 300E ICU unit?

I have pretty well diagnosed the failure within the ICU to output transistors
however Bosch has got a lock an key on these pieces of silicon... Can't find them anywhere and hate to dish out major bucks for a $1.50 problem..

I managed to find a reworked '88 ICU one for $375 but the best I price I can find for actually reworking the one on the car was $600....

The part number on the '89 is 006 545 6432 and the '88 is 006 545 6532.... Heck, it's just one number different!!! {8~)-

if any idea, it would be greatly appreciated...

thanks all.

Bob'o
89 300E