The 640-2 was made in 1954, used very little and sat for a lifetime so it's going to need some elbow grease to get going. But, it'll be a fabulous machine.
This minimatic is so cute and does a great stitch. I like that it has my favorite stitches from the 830 record. I use the serpentine stitch a lot in quilting. Yet, it's much smaller and lighter than the 830 so will be easier to move around. It took me a while to figure out how to remove the top to service it! Although it's a mini 830, there are some differences.