About the key ... I have two of these Bentwood Box machines, an electric long bobbin (as yours is) 128 from NJ dated 1951 and an electric 99K round bobbin from Scotland dated 1950. I did not have a key for either one and the 128 box was missing just the one locking mechanism that was screwed into the lid. I was able to find that piece on ebay and it also came with a squared ended key which opened the lock. But for the 99K which I had first, I used an old key from a really old suitcase. It was a flat key with a kind of small "T" near the end and that opens the box easily (like "lindyline" showed in the photo on page 2 of this posting)... kind of like using the small flat headed screwdriver. (The keys on ebay are ridiculously priced usually.) Maybe you have something like this in your house too. Anyway, it is a beauty and yes, you should keep it as it was gifted to you very quickly so I would say that your sister wanted you to have it. Enjoy!!!