The one I have on my 73 Comet is for a 69 Mach 1. It's fiberglass... I also have the Grabber spoiler. I prefer the Mach 1 spoiler...
I don't think it looks bad. Tim, from Somerset Ky. Has a grabber with the wing so it has both the spoiler and the wing and it looks good, to me. All the 69-70 sports roof stangs have the spoiler as part of the body style so to me it looks natural to have the grabber spoiler and stang wing together. JMO