When Miriam speaks of rebuilding tensions she knows from whence she speaks. Even if the springs are missing or mangled, they can be replaced.
Your Machine was made by J- A 15. Probably Koyo - Sieko for White / Janome. It is incredibly similar in shape, details, trim to my Aldens Deluxe ZZ model SUZ-2. I'd bet they were made for the same company.
Joe