I've appraised a few of these. Some really nicely done with contractors acquiring permits, adapting structural support beams, and the layout of the dwelling properly done so the flow from room to room is nice. I'll throw in the report the closest 4 bedroom model from the neighborhood of "what it was" then, the rest are 3 bedroom sales closest in age, construction, GLA, condition, etc. with all the commentary for the client. On these, in my area, the difference in value is negligible.
Now, you have "what sounds like" and I'm assuming, you have. Just a wall taken down with no permits, 2 closets and 2 doors to the same room. It's funky and the market will react accordingly. A good portion of the market (here anyways) won't want to deal with it. The ones who will, are going to want an entrepreneurial discount to take it on. I'm most likely not going to find any comparables with this same situation as well.
Additionally, it's not just putting the partition back up. Was there electrical outlets in that wall? How about the flooring? You should know as you're local and probably been in some homes of the same model.
So, are you going to have your clients sell "as is" and deal with the bumps in the road of showing, selling, appraisal, home inspection, and lending? Or, are you going to re-insert the wall properly and sell the dang thing with no hitches?
The whole second part is mute if I've assumed wrong.