I wrote:
> You are very close to the answer.  Try removing R9 - this will change
> the gain of the input amp from +2V to +1V.  With an offset adjust value
> around +1V, you should get what you are looking for.
>
> Why the change?  You have an input voltage range of -2V to +2V ==>  4V
> span.  You want an output span of +4V to 0V ==>  4V span also.  Thus, you
> need a system gain of -1 which your second stage already has.

Of course, I meant
"Try removing R9 - this will change the gain of the input amp from +2 to 
+1."
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