Sorry for raising an old topic.
The whole logo "controversy" seems to be due to a fuck-up by Garry Bushell, author of Running Free, who mixed Maiden's first logo - designed by Steve Harris indeed - with the one we all know. The first is the one in Blackletter (or Old English font or whatever you call it) and the ghost-like thing that can be seen on a 1976 poster. For the second one, Dennis Willcock simply used a font (already available) that caught his eye, so a) Steve Harris did not design this logo; b) nobody actually "designed" the logo from scratch, Dennis chose a font that was already there; c) there is nothing surprising in the fact that this font has been used by other artists before.
Yes, it would be interesting to know the actual name of the font, and perhaps even its creator, but both have little to do with Maiden.
Edit: Dennis did design the blood spurting lips though (Bushell calls it a "symbol" but perhaps it might be called a logo, I'm not a native speaker so I'm not sure). This might have added to the mess.