For example, I found a schematic that uses two inverting opamps to amplify the output of an AD590 with a gain of 1000:
In this case the second opamp appears to be doing nothing but "re-inverting" the amplified voltage as it has a gain of 1. Perhaps this has something specifically to do with the AD590, or the opamp itself (the LT1014), or perhaps it's just to use up an otherwise unneeded fourth opamp in a quad package?
Is it be a safe assumption that it would be possible to replace these two opamps with a single non-inverting opamp with a gain of 1000?
Edit: After probing around (and just looking at the bands on the resistors) it appears that R28 is in fact a 10kΩ resistor.