I would not worry too much about the foglights, many added them back in as it it very easy to do.
And most ACR's came with the comfort pakage of AC and radio.
If it's a real ACR it will have adjustable Koni shocks and different springs.
The registry does not indicate you can tell from the VIN.
But I would still call Chuck Tator at 914.763.3136 and have him look up the car as the computer may indicate GTS and/or ACR designations that are non vin related.
It's a good bet that it is a real ACR as the wheels are so expensive and rare at this point that it wiould take away any profit a fake ACR might bring once the wheels were aquired.
Another indicator is color, is it a stock combination? If not then there is an added chance it's a rebuild and modified during the process.
Another indicator is who you're buying it from, private party or dealer, we can vouch for many of the dealers in the market and are wary of some others. And if it's a Final Edition (red/white stripe) there is another registry that might give you some history.
Dodge Viper Final Edition Registry
Check the suspension and call Chuck.