[Healeys] Dust covers-ball joints

[Ghess4]

The rubber ball joint dust covers on my ground up restoration are less than
three years old and are already cracked and falling off.  I can't believe the
poor quality!  These were purchased from Moss.  The car is always garaged and
has been driven less than a thousand miles since the covers were installed
new.

Can anyone suggest a good quality source?  I have heard that a domestic car
part is a good fit but don't know the brand. I have replaced these on many
domestic cars and had them last well over ten years.

Thanks very much for any suggestions.
G. Alton Hess