No. It's just a simple thing we do here on this board. In each section of the Markers area is a sub forum for each type of marker. In the Spyder section there is a post that lists all the members of the Kingman Owners group. In the PMI section there is a thread for all the PMI/Piranha Owners. It's nothing special, just a simple list. If you'd like a graphic made, I can do that for you.
Just go to the Other Markers section on this forum and make a Diablo Owners group thread if there isn't one already. Before you make one, use the search button and do a quick search for it.
Did a quick search didnt find any. Under which "Mark Forum" should it go under?
Dogpatch, if you could make a good looking logo/banner and it doesnt take too much time go for it. If you do make sure you put your mark on it so people know its yours.