Pcv inside Breather?

Im having a ***** of a time finding the proper sized grommet for the oil fill holes on the MP black wrinkle VCs. Im getting tired of it leaking. I figured Id just get the twist on breather, drill out the top and put the grommet and Pcv in it. Anyone see an issue doing this? I cant think of any, but thought Id ask.
I don't know if it's the same size your looking for or not but I have some extras. I had a hard time finding them too for the factory size pcv so when I did find them I ordered extras. What are the dimensions of the one your looking for