Just behind the front passenger wheel arch - see arrow.That's link is helpful thankyou, where is the abs pump on a 172 ? Would it be obvious in photos ?
Good point on the lights, they won’t have the washers either.Headlights are another obvious one, far easier to spot than peering into the engine bay looking for an abs pump.
No xenon’s on a Cup.
If it’s the right colour, has the right interior and headlights I don’t think you’ll be wrong about it being a proper Cup.