Where is the fuel pressure regulator on my C70 convertible?

[Dusty Miller]

I am going demented trying to find the fuel pressure regulator on my 2005 C70 convertible. It is not under the fuel rail; it is not at the end of the fuel rail (although the local Volvo thinks it is and I sent them photos to show it isn't); it isn't alongside the fuel filter and I can't see anything like it near the steering rack. I think it's the cause of the car not starting in warm/hot weather as we have checked everything else. What I have found on the car shown in the attached photo has been described in info I found on the net (an info sheet of the control system fuel supply on an 2005 XC90) as control system, fuel supply -its the circular item which is connected to the manifold and then has a thin pipe which disappears. Does anyone know what it is? My car seems to be a rogue version as it nearly always needs the parts listed for another model. Help please.