Elna feeddogs
I'm using my beloved Elna 62C from 1973 to make pillowcases. The feed dogs have no manual adjustment - they automatically adjust to the fabric. The fabric doesn't seem to be feeding as well as usual. On further investigation, they seem to be quite smooth. This machine has sewn thousands of items, from silk organza to leather belts, so it's been heavily used. Can the feed dogs can replaced? Source? Level of difficulty?