@Jeremy,
If Tony's friend could be persuaded to divulge the source code, we wouldn't need to decompile it; it has to be hand-coded assembly language, so turning it into C code is unlikely to help, I would've thought¡ I suppose you'd get "structured" assembly language, but then you'd have to feed any modifications back through a C compiler, which would be unlikely to produce machine code of the same density. But I'm just guessing here, so I'd be interested to hear your thoughts.
The decompiler is just for figuring out how code works, rather than recompilable C.
Yes, it is 'structured' with loops, and no registers, etc.
The whole point is to see the program at a higher level, but with far less effort than doing it by hand. Say, 2 weeks instead of 2 months.
Cheers,
Jeremy.
