Hmmm, have you tried emailing pbresource? They have the R-111-39 grommet. See the link below, scroll all the way down.
http://www.pbresource.com/bells.html
Not sure what the difference is between that and the 29, but they may have them and just not list them. In my experience, they're the same as a hardware grommet, so long as you can find the right size.