This one is from Reality In Scale called The Old Wall , it's a complete resin kit , a nice "little" background for a diorama width 27cm ( about 10" ) .
I have sprayed the whole thing with white rattlecan primer , then I've filled the damaged areas with a waterbased concrete color from Woodland Scenics . Then highlighted the bricks with Revell #37 brick-red color , followed with a bath of the concrete color but strongly thinned this time to simulate some mortar still sticking on the bricks .
Now to my problem after trying several different ways to add some age to the wall (all removed again) I need some tips because it is definitely too white/new .
I was not satisfied with the griffons on the doors different size and height so I removed them , still need to rework the texture ... it came out worse than I thought after the first layer of rattlecan red brown primer .
Any ideas 
are welcome 