What to use to clean the outside parts always seems to be the hardest information to find. I think that's because so many people prefer different things and what works fine on one machine can totally ruin another. It's a difficult thing to figure out. The one thing you can always use and it will not cause harm is sewing machine oil. Oil works really well on machines that are already in decent condition and the finish is not terrible degraded. If that's the case, then you must read-read-read and pick your products very carefully.
I've noticed a number of times when I read an article on cleaning they will tell you all the things you need to have on hand (except what to clean the outside!)
On another note...display only? Are you sure you don't want to free up the insides and get it working again?
