how to add PVC and Oil filler cap to new valve covers

[88Stanger]

Ok, so i bought a nice set of brand new aluminum valve covers that do not have provisions for a PVC or an oil filler cap.
1.) So, if i am not mistaken, i can get a PVC valve and grommet setup, drill a hole in the valve covers for the grommet and PVC. Does it matter what side the PVC goes to?
2.) I am not sure what i can do for an oil filler cap. from what i can tell there are no provisions on the underside of the valve cover for this. So i am looking for some ideas here. One is to find a bung that can be welded to the valve cover that i could then put a screw in plug. Not the best, but with a funnel it could work, the only bad thing is that i do not have a heliarc or know someone who does. So any other ideas is appreciated.
Thanks for the help.
attached is a pic of the covers