Heirflick, hope you had success removing the decals & Johnsons Kleer? I have just removed Kleer from a Bachmann US loco tender. I used a solution of caustic soda in water applied with a cotton bud, then scrubbed the area gently with a small sponge and neautralized the caustic solution with water and a wipe off with kitchen towel. After its dry, 24hrs, any white marks need removing with water & the kitchen roll and leave to dry again.
So Far,36hrs, no ill effects to model or to the paint and no paint was evident on the cotton bud during the process. On the bottle of Kleer it suggests using ammonia to remove Kleer from floors but I had no ammonia!
Shall not be using Johnsons Kleer on any models again.