What I did was to spray on upper surfaces the same very diluted white/yellow mix I used for the D.520.
The goal here was to fade down the RLM68 colour to show the effect of sunlight inevitable, i.m.h.o., in that Middle-East environement.
I still have to add some weathering, not much but some, and latest details.
Your comments/suggestions are wekcome as usual.
Alberto