Hey Nick, yeah just OFS/FFS as I don't have any SFS or PFS disk images to test.
I want to add real drive access later too.
Once all that works, I'll see about supporting other file systems.
To be honest the real fun is making a "workbench" clone to access them... there is also a 68k emulator in there too... just not doing anything at the moment 
I was actually wondering if you'd done it that way so you could use the actual 68k filesystem handlers. Well done, I'm impressed.
I've not got a working Intel Mac anymore so I can't have a play with it sadly. Maybe I should build a Hackintosh.