The inlay credits refer to SB Graphics, which was a Birmingham graphics design firm that no longer exists. The artist that worked on the inlay is Brendan McMahon, the same artist that drawn the map signed "Bren the Mapmaker" inside the instructions.
Remarks:
ZXSR: Roger Kean (the Crash editor at the time) came up with the idea of having all the doors numbered to help memorise the map.
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