Resealing my mk4, I managed to get the valve out and reseal, but you have to leave the end with the oring loose to slide it back in, has pin holes in the end like a Taipan or Kalibrgun hammer spring adjuster, only it’s about 10” in the tube. Am considering making a long wooden dowel with pins pressed in or calling AOA on Monday to see if I can borrow one. Thanks Rick