Doh, just typed a reply and lost it because the forum didn't like my attachment... 

Anyway, have now attached "CODE" as "CODE.txt" but it's really just the main binary.
Not sure what version of ST bloodwych it is, other than it's a true STX image of an original disk - not a trainer or demo.
Your offset explanation makes perfect sense - hoping to get some more time to work on my code later this week.
Is there any significance to the "special" floor, any why it would be different between ST/Amiga?
And what are the wood traps?
Below are the ST addresses for this binary:
From      To      Ingest      Notes
0x00000   0x589D   No   Unknown
0x0589E   0x058DD   Yes   Buttons K
0x058DE   0x0591D   Yes   Buttons S
0x0591E   0x0595D   Yes   Buttons M
0x0595E   0x0599D   Yes   Buttons D
0x0599E   0x059DD   Yes   Buttons C
0x059DE   0x0601D   Yes   Buttons Z
0x0601E   0x06DB3   No   Unknown
0x06DB4   0x06E33   Yes   Triggers K
0x06E34   0x06EB3   Yes   Triggers S
0x06EB4   0x06F33   Yes   Triggers M
0x06F34   0x06FB3   Yes   Triggers D
0x06FB4   0x07033   Yes   Triggers C
0x07034   0x070B3   Yes   Triggers Z
0x070B4   0x0EE3B   No   Unknown
0x0EE3C   0x1023D   Yes   Floors And Objects K ($28 bytes other header data still to account for)
0x1023E   0x1163F   Yes   Floors And Objects S
0x11640   0x12A41   Yes   Floors And Objects M
0x12A42   0x13E43   Yes   Floors And Objects D
0x13E44   0x15245   Yes   Floors And Objects C
0x15246   0x16647   Yes   Floors And Objects Z
0x16648   0x17474   No   Unknown
0x17474   0x17476   Yes   Monster Count K
0x17476   0x17478   Yes   Monster Count S
0x17478   0x1747A   Yes   Monster Count M
0x1747A   0x1747C   Yes   Monster Count D
0x1747C   0x1747E   Yes   Monster Count C
0x1747E   0x1747F   Yes   Monster Count Z
0x17480   0x1777F   Yes   Monsters K
0x17780   0x17A7F   Yes   Monsters S
0x17A80   0x17D7F   Yes   Monsters M
0x17D80   0x1807F   Yes   Monsters D
0x18080   0x1837F   Yes   Monsters C
0x18380   0x1867F   Yes   Monsters Z
0x18680   0x590FA   No   Unknown