If it is that old, it may simply be that the part is no longer available or hard to find. But I know from experience repairmen will tell you"you have an old machine, you would be better off trading up and putting money toward a new one."
Not if i really LIKE the one I have, thank you. I have a Kenmore-24yrs old-one of the first computerized ones. I did put about 250 into it a few years ago and it is just fine. It is my back-up and the one the girls go to when they are home. Honestly, it has some features my newer Brother doesn't have, i have no desire to get rid of it.