While visiting in Southern California, I found a posting on Craigslist. Drove over and got a brand new in box M1950 with (2) copies of the technical manual. 40 USD. 1 question: How is the lower pump cap properly threaded on so that the upper pump cap properly seats? The manual mentions to be sure the pump tube gasket is seated properly after attaching the lower cap. It came properly seated. Where do you thread the lower cap to be in the proper position for the upper cap to ensure sealing properly? If you own one, I think you will know what I mean. Thanks, Ken Here are 4 photos I took today.