The Corvus Concept's been sitting in a quasi-broken state for as long as I can remember (at least back to 2006, maybe more). Run by itself it'd hang on a white screen; run in the debugger it'd show a POST failure.
Let's fix that up a bit (this is now what you get with just 'mess64 concept'):
Next up: hook up the Apple II slot bus it borrows/perverts and try to get it to boot something