Did the lead between the ignition switch and starter get accidentally disconnected when the IAC valve was being reinstalled?
Yeah this is possible too (I can't recall how it's routed), I didn't think of that!
Also, is your starter motor one of the new fangled lightweight types, or the old school big black buggers?
I don't really know ... all I know is that it was either new or reco, and it bolted into place. I suspect it was black, but I didn't start with an engine & 'box in the car so didn't have an original one to notice any differences to.
The battery is only about 9 months old & sits on charger/maintainer thingy (forgetting to flick said device is what killed the prior battery), so I doubt it's the battery. Actually, if it were the battery I'd see the voltmeter drop tragically as it tried to start wouldn't it? I was a bit "don't have time for this" yesterday so didn't investigate far.