Caroline, help for your Elna
Caroline - nice machine! The cabinet, very very nice, and solid! Congrats on a great find.
I recommend you join the yahoo group called elnaheirloomsewingmachines There are some incredibly experienced and helpful people there who will help you get this girl stitching again.
I am certain that you will not need to replace anything. Just a RGC. (Real Good Cleaning) ;-)
If you do need a new bobbin case, I have another Elna which I am cannibalizing for parts, so feel free to be in touch when you get there, rather than buying a new one, in case my bobbin case fixes your woes. But honestly, I don't think you are going to need to replace anything.
Again, congrats. I think you got yourself a workhorse of a machine there!
-Cecilia