It is really easy to tell the ATE from the others once the wheel has been removed. Right in front of the area where the pads will be removed from the caliper, you will see a sheet metal ribbon shaped piece that is held by two drift pins, these are the ATE pad retainer springs. Other brands use different devices here.

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150