:curse: I have to say that I am not that impressed with low-relief structures. Unless you have a way to disguise the side, your visitors won't be impressed. The best you can hope for is building the entire backdrop with low-relief structures so that they hide the sides themselves. And if this isn't practical, perhaps use a scenery "divider" at the exposed ends.
announce1Also, if you really want to get close to the back wall, do what I did - I kitbashed full depth structures by removing about 1/3rd of their depth. Then, at the exposed end, I used a drive-in carshop with a spur track going inside. All of the connecting structures are built the same way, with openings in their side walls to push cars into, so that what I had was a hidden siding that is only 2" from the wall!