Originally Posted by Macybaby

Most of the Manufacturers except Singer put "badged" names on the machines they sold. National is recorded as selling machines under 600-1,000 different names. And some companies (like Sears) contracted with several different manufactures, so the name on the machine may not be helpful in determining who made it.

If you can post a picture, that is the easiest way to identify who the manufacturer is.
If not - is it a VS or rotary machine?
Does it have a top leaf tension, if it does, that is also usually unique by manufacturer
What shape is the needle plate - round, oval, square, rectangular?
What do the slide plates look like, and if rotary, how to the move (do they have a pin and swivel?
What side does the belt go on the flywheel - towards the machine or away from the machine?

How does the presser foot attach? Top clamp, side clamp or directly to the bar with a set screw? Note - most manufactures mounted directly to the bar for older machines, and converted to top clamp later.

I have over 150 vintage machines, and one of the fun things was learning how to identify the manufacturer.