Apologies for the bump, but I finally got this working!!!
Using the latest FS-UAE (complete with Blizzard ppc settings) I created a copy of my A1200T, using the A1200T's self-same WB39 drive. The game ran straight away, with no tinkering.
However, running it on my original 1200T, the game would hang just as Level 1 starts. A quick squiz through this thread and the 'NOCACHE' Tool Type option did the trick.
Oddly, the Tool Types for the game had 2 entries for preload ('Preload' and 'PRELOAD'). Commenting out either (or both) of these didn't seem to affect gameplay, although the System 3 loading screen flashed a bit with 'Preload' commented out.
Anyhoo - It's working and I'm chuffed, and I'm playing it while I should be working!