> I'm imagining going through the image fragment and identifying all
> pointers to destroyed space and replacing them with .... maybe nil,
> though I'd need some way of identifying where the damaged pointers
> were to verify what happened.

The trouble is that most likely one of the missing objects is the active
context (often the "last" object in the image file). Restoring it is tricky
but not impossible.

> So far I've restrained myself because this seems like a potentially
> big and slightly silly project.  But is it impossible?

It is most definitely not impossible; just very hard. If you want to do it
yourself give it a run using the simulator (and have the Squeak book ready -
some of it will be helpful in understanding how this stuff works under the
hoods). If you're desperate, consider throwing some money at the problem -
there are verious people out there who could do it in a couple of days I'd
think. It *can* be done, the question is simply how much that data is worth
for you (both in terms of time as well as money).

> (Ideally, I'd replace each bad reference with a stub object that
> included the pointer, so I could tell which stubs were pointing to the
> same place.  The problem is that I have no stub class in the image.)

The simulator can do anything you want - it's just not exactly trivial to
make it happen.

Cheers,
  - Andreas