While filling some gaps with a mix of Green Stuff and Brown Stuff, I also added some to the slotta tabs, to create a stronger bond with the base.
After priming the models with white from an Army Painter rattle can, I painted the bone in the scheme that Mike McVey explained in the Warhammer 4e Rule Book color section: two parts brown ink : two parts yellow ink : one part water. I read that recipe in the beginning of the 90s, but it somehow stuck. When I started to paint the beginning of my undeads about 15 years later, I still had it in my head and used it - as I did ever since, whenever painting bone basically.
The ink was followed by a drybrush of bone white (the easy method of the McVey article),
which was followed by a drybrush of white.
Then I painted the cloth, rope, etc.; giving everything a brown or black wash before highlighting, to represent old and dirty cloth.
For the metals I used Dirty Down Rust, and for the bottom of the catapult I used Dirty Down Verdigris for some moss effect.
The bases I painted with my standard black/brown mix.