I recently purchased a used Bogle-Greenwell Model SHS sewing machine. I believe this is the same class as other 441 clone machines (Cobra Class 3/Cowboy CB3500 etc.). I found an oiling diagram for a Cowboy CB3500 online, and used that to lubricate the machine prior to purchasing. I was able to get the machine running and made several test stitches. However, the rear Presser Foot is not moving, up and down, when the machine stitches; it just keeps constant pressure on the leather as the needle and needle foot move the material. I started doing leather work about a year ago and have very little knowledge about working on/with stitchers. Any advice or resources will be greatly appreciated. I've attached a picture of the machine and the presser foot that is giving me issues (RED arrow).