Your machine isn't showing its age.
It sounds like your foot control. Is it a modern, electronic foot control or a vintage carbon pile one he had on hand?
Is the machine binding up? Un-thread it and remove the bobbin. Using the hand wheel, slowly turn it toward you, see if there is any place it catches or stutters as you make a full revolution. Do it a couple times to make sure every thing is OK or to make note of where in the needle stroke the binding occurs so you can repeat it for the repair man.
While you have your bobbin out, put a drop of oil in the very middle of your bobbin case. There may be a hole or a wick in the center of it, either way, the oil isn't going to hurt anything and your machine will thank you.