The Arvin Meritor catalogs have some nice pictures to help find parts.

I take the numbers I find in their catalog and then cross reference them to Napa parts.

This helps a lot for parts that my local Napa says are impossible to get.

Here are direct links to the catalog pages:

Wheel cylinders 1 1/4 and smaller
www.arvinmeritor.com/tech_library/documents/2_146-162.pdf

Wheel cylinders 1 1/4 and bigger
www.arvinmeritor.com/tech_library/documents/2_163-171.pdf

Master Cylinders
www.arvinmeritor.com/tech_library/documents/2_172-188.pdf