Mine is the boye shuttle number 7 and I think that should be yours as well but I am not sure. When I have a bit more time I can look to see what the shuttle and needle takes
Here is my take on it
50$ is good for it. I love my domestic never have problems always a great stitch.
If you are looking to sew on it everyday and are not looking to add to a "collection" then I would say pass on it. The shuttle can be hard to find and I have paid 15$ for 10 needles (sometimes I have seen them for more)
So it wouldn't be good to be sewing all the time on it.
If you just want it for sometimes sewing and more of a conversation piece then I think its okay you could possibly do a better deal but $50 is not bad.