Your building troubles me. I can imagine that the stucco mixture was
fantastic. I nearly died when a house here in Oak Park, IL which had that
wonderful mica-sparkle stucco was PAINTED OVER. NO NO NO NO.
But in the case of the house you are dealing with. The very first thing is to
make all the proper roof repairs. You have considerable deterioration on the
outside face at the parapet wall. That indicates that there was failed or
improper flashing at the union between the roof and the backside of the
parapet wall. Water has probably been pouring down over and through the
stucco for quite some time.
The cracks in the stucco need to be repaired. THese cracks may still be
"moving" which calls a more elastic type of caulk/sealant. The surface should
be "sounded" to remove all those chunks of stucco which are detached from the
substrate, and are about to spall. The stable cracks, and the now gaping open
spots will have to be patched with a stucco mixture which is similar to the
original (similar in lime : cement : sand proportions.) It is going to be
tough to match the decorative stucco finish unless you have a really skilled
contractor. Edison coatings are a good start. If you can match the stucco
finish, you may be able to get a good patching job (but the joints between old
and new will always show - unless you give the whole building a "skim coat" of
the patching stucco.)
Another option, although you will lose the mica finish, would be to make all
the repairs describe above, and then coat the exterior with "Keim"
cementitions coating, over a fabric mesh. Keim colored finish is then applied
-- it is a mineral coating which does not peel like paint because it is
mineral -- I'm killing mysef here -- contact Keim (in US, Mame Cohalan,
Cohalan Co. , Lewes, De.) You would get a good overall surface which should
be long lasting, you would no longer see the cracks, but you would not have
the mica / sparkle effect.
Good luck. It's not an easy answer. And it will cost quite a bit. Fix the
roof first and work your way down.