RE: finishing problems
For removing any decal adhesive use an "adhesive remover" There are industrial strength brands I use for my business for huge removal jobs ( about $50 a gl).
But Ace hardware sells a 3M adhesive remover- get that.
Get area wet with remover, Let soak for 5 minutes . Gently rub off. Repeat process if needed.
Other chemicals tend to buff the finish or even take off color.