Hi,
The New Home Rockford database shows your LN serial number to be from 1949 to 1952. I was surprised at that date range and being made in Rockford, Illinois. See your Free Westinghouse name plate for Rockford, ILL labeling too.
The front and rear slide plates suggests a 'torpedo' shaped shuttle or bobbin case Your bobbin winder should take those long 'dumbbell shaped' small diameter bobbins. See below.
These are not your manuals but they have items that should get you started. Manualslib.com.+
https://www.manualslib.com/manual/89...?page=6#manual
This page shows info on the shuttle and other pages. Ignore it is a treadle manual or Free Sewing Machine from before 1940. Page 20 has Instructions for electric machines!
On PDF page 5 is how to thread this machine, the actual manual image page is 9.
This page has a Free Westinghouse manual for download and for free. It has a thread width adjuster I don't see on yours. However, it has your bobbin winder or one similar. It should operate like yours or close enough to get you started.
http://www.doubleveil.net/zssmp/expertbt.htm
Keep in mind that Free Sewing Machine, New Home, Free Westinghouse, Elgin, and other third party brands are the same or similar models and manuals to your machine.
I have a friend that is a technician at a very credible sewing store. He showed me various bobbins on old treadle machines they had in a collection. He told me that those long dumbbell shaped bobbins look the same but had unique different dimensions. So, don't just buy some extras on ebay that just look right. Ask for dimensions.
In the Zorba online manual PDF on page 26 is item 133 near the center and left a bit.
That is what I believe is your bobbin shape and page 28 calls it a 'bobbin complete'.
This is for a White machine but it is what I think you use.
https://www.ebay.com/itm/WHITE-Shutt...oAAOSwhpZaQAET
This ebay view shows the bobbin close up for this White brand machine.
I hope this helps a bit. Hang in there. Others know way more than me but I am going through the same process as you. Getting the right parts and manuals is not easy on my green wrinkle finish machines from New Home and Free Westinghouse.
When you think you have everything set up and threaded, only hand crank the hand wheel to see how things are working with some fabric like one layer of jeans.
Jamming a needle into a bobbin case under electric power is a no-no. Go slow at first. Don't force anything.
Breaking off a needle is not good.
Stefan