I saw the topic that Trailer Park sent about the Martin & Schwartz visible pump. I am new in this field and I also have a Martin & Schwartz visible, Model G500. Some of these pumps were used up here in Alaska in the last 15 years. I have the pump stripped down and I also do not know much about the Martin & Schwartz visible and by the books I have read there is not much information on them. I would appreicate any information on these pumps. I need to get this pump restored so I can get back on my strret rod.