I’ve been working on an old Necchi BF that my wife got a long time ago from her aunt but never used. The movement was really tight and I’ve been using penetrating oil to free it up. It’s much better but I seem to have hit a point where there is still a very small amount of resistance when the needle raises all the way and it’s not improving. I think it should be completely smooth through the entire cycle but thought I’d ask before I keep trying to achieve something that may not possible. Should there be any noticeable, no matter how small, difference in how smooth the movement should be? This is just turning the whee by hand. Thanks.