Hi Sue,
I would keep it and keep fixing it as long as possible. It has sentimental value to you. The newer machine are not being made with the same quality and are not lasting as long in some cases as the older machines for various different reasons. I still have the machine my parents bought me when I was eight. I will never get rid of it. I also have my mom's machine that she used all her life that I'll never part with.
I also have to ask in general, not to you, what's up with Bernina anyway? Why do they design their machines so that the feet will not transfer from one machine to another? This has been one of the reasons why I've not purchased a Bernina to date.
I bought a foot adaptor that attaches to any type of shank. With this adaptor I am able to purchase any foot that will snap into the snapper end (not the right terminology). I just love this feature, as I can use any brand's feet that will fit the adaptor, as well as it changes to a different shank if I change machines.
Why wouldn't this type of adaptor be able to be used with the Bernina machines?
Pam M