The rectangular bit on the 201 is solidly tightened to the round presser bar (the rod piece), and should move up and down with the rod. I'm guessing you need to keep on oiling all the points there; take of the shiny screw on top of the machine add oil down there; be careful not to misplace the small washer on top of the spring. Make sure oil seeps down the black cast iron part of the body where the metal rod (should) move up and down. There should be oil on the back side of the presser bar lever too, it pushes the rectagular bit up, and needs a bit of oil to move it smoothly.
You should with a bit of force be able to grab the presser foot and push the bar up; if you can't do this when the presser bar tension screw is loosened it's stuck. The square bit needs oil too, just add oil to the cut out groove in the back of the machine, where the presser foot moves up and down. It can gum up to by dirt and grime, but it's usually the part the rods moves up and down in that needs particular attention.