I have learned to CLEAN vintage machines with decals by using sewing machine oil and cotton balls or soft flannel cloth.
Only in the very very worst cases will I use Hoppes #9 gun cleaning solvent as it's mostly kerosene and to date has not damaged any decals for me.
Denatured alcohol and to a lesser extent rubbing alcohol are solvents of a different nature and I don't let them near the finish on older machines.
I really don't know what to do to clean the smeared decals on your machine.
Joe