Me too, Chris. The height of that custom poster (likely locally produced) looks to be about 84" tall. The perspective is a little off, since it is more in the foreground than the crowd or theater usher, but I bet it is close to that height.
What is curious, too, is that the image of the lantern carrying grave robber is the same as the Swedish OS. Aside from that one poster, I have not come across any US paper image that features this design. So perhaps some as yet unseen US style (OS, insert maybe?) featured this, too.
The digging continues.
As a side note. Also worth noting is that both the "special" 3 sheet teaser and half sheet used an image of Karloff in an earlier makeup that was not used in the final film (but was featured on the US OS and other publicity materials as well).