In the case of my 94 E320 Wagon (with dust filter) it was possible to buy a Bosch replacement motor without the cages. It does take a little fiddling to remove the cages from the old blower assembly and install them on the new one but it is possible. If I remember correctly the motor was less than $100.

J. M. van Swaay

__________________
1994 E320 Wagon, 230,000 miles
1995 E320 Sedan, 106,000 miles
1994 E500 Sedan, 79,000 miles