Tashana
STOP< > STOP <> STOP!!!!! Stop with the chemicals and scrubbing. That milky looking dirty appearing surface is most likely the old shellack that has turned. Once you scrub through that you'll leave those most fragile decals exposed and they'll not last long.
I found out the hard way on a real nice red eye 66. Before we knew what we were doing we'd ruined what decals were left. The machine still runs great, but it looks terrible now. At least to me.
Oil and soft cloth to clean. Take your time, it didn't get dirty over night, it won't get clean over night. When the cotton balls, flannel or soft material stops coming out dirty, YOU'RE DONE. STOP.
Then go here to Glens tutorial on refurbishing the finish and use that if you must.
http://www.quiltingboard.com/vintage...s-t193635.html
Joe