hurleyjd said:https://www.johnblue.com/contact-john-blue-company.shtml Email: [email protected]
You might send the photos to the John Blue company and see if they can help.
hrsr said:I have a LM4-955 that looks very similar if not the same as your picture. On mine three of the four pump chambers have part numbers visible that are stamped into the metal. These numbers match the numbers in the manual you posted. I also have a single piston John Blue which has part numbers stamped into the metal.