That is a really nice machine. I've never had the chance to work with one. Not yet anyway.
I would be very careful about cleaning that machine. You are already down past the shellac in most places. The filmy areas is the old shellac.
I wouldn't use any chemical cleaners on it either. Just sewing machine oil and cotton pads or balls.
After that read Glens tutorials on cleaning the finish on the old machines. {
http://www.quiltingboard.com/vintage...s-t186522.html }
Oh and that green pseudo antiquing .............. ugh. I do hope you're gonna eventually get rid of that and put a proper finish on it. It would be soooooo much nicer.
One more comment, be careful how much weight you put on the cover when it's open, too much weight will pull the screws out of the wood.
Joe