I agree that it is getting harder and harder to find specific parts or presser feet for the older machines.
I have been on the hunt for a Bernina older style #62 presser foot for quite awhile with no luck . I have left my name and number with many repair places just in case they might come across a used one. (if you have a source please let me know)
My local OSMG retired 3 years ago and I truly miss his knowledge and ability to find a part or foot for one of my vintage machines. He was a great source for info and help whether it was to fix a machine or find a used part/foot for a specific brand of machine. I have come across a few "new owners" of sewing 'repair' shops that are within a 4 hour radius drive from me and they are not interested in the vintage stuff - told me they wouldn't touch it because they are too much work and don't yield a profit - some just toss the "old stuff" out
I realize that there are many terrific newer models with newer technology that can do wonderful things but I love the sound and feel of vintage machines. I marvel at "their" abilities and "their technology". It makes me sad to know that even in a few more years it will get even harder to find parts to help them "sing" again and run like they should. Guess I will have to search a little harder and try to be more resourceful.