Applying earthen or lime plaster on top of cementitious/painted wall?

Hello,

I am in the process of restoring an adobe home from the 1920s. The home (like many in my area) unfortunately has a 1/2" cementitious stucco layer on the exterior walls, which was then painted over with several layers of paint. The stucco is coming off in some places, but for the most part seems well attached to the adobe.

The same same thing is on the inside, though there are more layers of latex paint, and the stucco is still adhered.

It is a dream of mine to restore this to earthen or lime plaster inside and out, beginning with the outside since it's in such bad shape. My initial question is this: does it make sense to apply the plaster on top of the cement/paint layer (assuming I can get good adherence)? Or would this create issues with permeability?

I can't seem to find much info about natural plastering on top of existing walls, most of the info I am reading in my books/online is about new builds.

Thank you!

  From what i have read there are mixed opinions on the cement stucco.  At 0.5inch thick it is vapor permiable just less so then lime stucco.  Since i have found adobe and rammed earth experts on both sides of the cement stucco issue and you say it is bonded well.  I would leave the stucco that does not come off when i give it a push pull or 2,  and small hammer test, you can hear the difference bettween loose and bonded stucco.  I would not fight it, if it wants to stay let it.
  The paint needs to be removed.  Exterior oil based or latex paint is a vapor barior.  
  I would pressure wash the wall and then wire brush the wall to remove most the remaining paint and loose stucco.  You have to scratch the wall for the new lime stucco to have something to "key" into anyway.  This is just 3x as much wire brush work to remove 99% of the paint.  
  This is exterior only, i would work on the backwall first and find out how much work it is and test, learn, what tools and process work best.  Before i did a public visible wall.   Tom