|We're having an adventure... JUST LIKE THE GOONIES!|
I think that these were originally created by pasting up photocopies or the like and so many of the elements are used several times. I used the same system but did not have time to completely polish each final image so there might be some oddities and inconsistencies.
Another issue was the the squares were actually 7/8" and not perfectly square so they won't always match up. I think they were meant to be rooms and not necessarily tiled together so this would not have been a huge issue. And trying to put them together leads to a lot of awkward floorplans with portals going into the back of computer banks etc. The versions posted here are exactly 4"x3" and I've included a blank image of the floor-tiles so you can use them as connecting corridors.
Let me know if you know of more than the six designs shown here and if you plan on using these in your own Star Frontiers games.