You got a great cabinet! I too believe it is original but they do usually put a metal tag inside that tells you. That machine is also a zig zagger and should sew just beautifully. They are really quiet machines.
I went back and looked at the accessories you had with the machine and all I see you need is the handle for the buttonhole cutters and I think the rods to attach the Wonder Wheel to the stitch controller and the needle positioner. I have never used the Wonder Wheel so I'm not sure how well that works. Seems like you've got everything else you need. Saw a metal plate with the accessories in the other thread, check and see if that goes to the machine or the cabinet.
http://www.ebay.com/itm/Vintage-NECC...IAAOSwa-dWsSxm
Hope the link works. I attached only so you could see the metal rods and watch or see if they are among the pieces you have. That listing is really high and I have learned the hard way that patience truly is a virtue! I too will look and see if I have any extra. May take some time but should get to it today and then will let you know!
Hope you get everything oiled and moving smoothly because they are really nice machines!
Lisa