Stop in for a cup of coffee

In the '67 book, the dust cap for both the disk brake and the drum hubs is in Group 22
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According to this, the 10 drum, K-H and Bendix hubs all used the same cap.
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I recall having ending up with the wrong cap a few times - wayyyyyyyyyyyyyyy pre-internet. Heck TRS-80, Commador PET, and Apple were something only a few people had (not me). Best luck was with dealerships had the old books and good parts managers.