I just acquired a Necchi Model 536FB, other number found on machine 10534. It sews great and everything seems to be fine, except for the drop-feed knob. It has two options, for straight sewing put on the part of the dial with broken lines, and for the feed dogs put it on the part of the dial that has a figure similar to tic, tac, toe. It is now on straight sewing (it came that way), the problem is that the knob will not move. I don't see how you could oil this. They do have a screw on the side of the knob. I tried to unloosen it, but cannot budge it. Does anyone have any suggestions for my dilema? Also, how can I find out what year this machine was made. I went online to the Necchi site, but could not find out any information. Would appreciate any help you can give me. Thanks,
Lucy