Miriam, I can't thank you enough for posting this! I am still learning about my beautiful vintage babies and I hesitate to take anything apart (unless my hubby is sitting right beside me) for fear of breaking it or not being able to reassemble it correctly. Your tutorial will help, the feed dog screw on my 15-91 is getting very difficult to turn, so I guess I need to try to clean off any dried up oil. If you hear loud weeping, you will know I somehow managed to break it and will be asking for help...
Thanks again for doing this!