Hello Brickboard. After a break, I am back to rebuilding the fuel system on my barn find 1974 145. The tank is refurbished, the pump and accumulator are new, the lines are all new and the injectors are cleaned and ready. After much research I decided to take on the fuel distributor rebuild myself, (with some sage advice from an engineer friend), but, after carefully dismantling the distributor and with a rebuild kit in hand, I discovered that the control piston on the system pressure regulator is missing. I have no idea how this came to pass, because the car was a true barn find, sitting nearly thirty years with no back story. The distributor is a Bosch 0438 100 003. I have contacted most of the usual places, but with no luck. Here's hoping that someone out there might have a lead on where I might be able to source one of these pistons. Please help if you can. Warren