Nice!
I like the way it has a modern style to it without losing the feel of the orginal
of course once you've got the original boards done (and I guess the ones from Mission Dreadnought and Eldar Attack too) you could start making more variants with different layouts and special rooms
Personally I'd still go with having the door places marked on the walls, my group tends to slide the Space Crusade doors to one side to show they are open and side them back when closed - I've seen people take the card part of the door out of the stand to indicate an open door, but I find that chews up the card more quickly. Also it makes it easier to see were a door is supposed to be when they get knocked over during gaming.
HeroQuest doors of course had open and closed versions - are you planning to do your Space Crusade doors with a similar sort of idea?
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~The ravings of a single mad Goblin is bad enough, but such a power-hungry, malice-filled creature as Mortis can never hope to be understood~