The dust caps worked fine. I had to make a composite one from two different kinds to approximate the type I was replacing. I cut a 3/4" hole in the solid one, and cut-out a slightly larger disc from a screen-type and glued it into the solid one.
So I ended-up with a solid dust cap with a screen center. Both types served their purpose in my particular situation.
Reviewed by: Philip W. Starr from Groveport, Ohio on 4/19/2012