Fuel Pressure Regulator Recall

According to GM service recall 03054B for the fuel regulator, if the regulator is Bosch, there is no need to change it. If the regulator is Delphi, it must be replaced. When GM did the recall, was the replacement a Delphi? Is there any obvious physical difference between the original regulators and the new replacement? How can I tell if recall was completed on this vehicle without going to a dealer?

Call the dealer give them your vin and they can tell in minutes if the recall was done. then there is no doubt.