Replace the seals right away since some are sticky. My old Contax 139 got like that before I knew it and some of the sticky seal material crumbled and got on my focussing screen and made a mess.
Congratulations on the camera. K1000's are great. A good friend of mine bought one in the early 1980's and it still works fine. Back then they were the most highly recommended 35mm cameras by college photography teachers. They were great reliable cameras with quality lenses for a relatively inexpensive price.