There are from what I know only the 3 official flyers/counter top type promotionals that you already have for the palitoy mail aways, there's others but as you have suggested only in the form of comic book adverts like the Dengar.
There are others for clipper / PBP etc but I think just those 3 for palitoy, if you chack the baggie guide on page 5 (mailers section) you can see the other known types for the mail in promtions as well as a few others.
There is also a much larger poster size one available for the Emperor that I have seen (exactly the same just large) not sure if they made the poster size for others, but I have to date never seen any & only ever one for the Emperor, so who knows.