4000Q Fuel Q: FPR or fuel distributor

[SuffolkD at aol.com]

1986 4000Q.
Investigating the Bentley I find my two items of interest:
Page 20.9 has an exploded view of the CIS-E
then on 25.73 the fuel distributor is broken down.

The two screw thingy is the Differential pressure regulator
and the Fuel pressure regulator is a diaphragm pressure 
regulator................
off for testing............
PREVIOUSLY,
Quick Q about the two screw thingy on the front of the 4000 Q JT engine fuel 
distributor.
Family Album doesn't clearly show the exact part number
1986: MG 1 SG 33 Ill 19-00
1A Pressure regulator PN# 026 133 482
or
7A Potentiometer for ECU cars PN# 035 133 472B

Which is the the two screw thingy? facing the front of the car?
Is this NLA or does anyone have a replacement/used one?  
-Scott by BOSTON
car running rough w/ hestitation in the lower RPM and poor power.