The Fischer Plath brand of aluminum washers (in the size you are looking for) are available from our sponsor at 25 cents each:

Aluminum Washer - 30 X 36 X 2 mm
Part #: 30-X-36-X-2-AL-M131

1985 Mercedes-Benz 300D Base Sedan - Miscellaneous & Hardware - Page 2 (about halfway down the page)

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78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022