Here's a solution that worked for us. We lengthened the rails so that the longer queen mattress would fit between the head and foot boards. Then we just laid 2 x 4 crosspieces across the top of the rails to hold the mattress. By opting not to mess with the width of the bed, we didn't have to worry about the connecting system. Granted the mattress is a bit wider than the head and foot boards, but it's not really very noticeable. It does raise the height of the mattresses by quite a bit, but I like a high bed, so this wasn't a drawback to me.

I need to change my response. I could have sworn that our master closet was the same color as the MB (SW Blonde) and I know that it was supposed to be, but today I looked at the closet and the walls and ceiling are both SW Dover White! My husband changed a lot of the paint colors on his own (GRRR!--he's afraid of color) and this is one change that I missed, but after thinking about it I'm glad that it is light color as we only have one small window in the closet so it would have been dark. We have 3 other walk-in closets and they all have SW Dover White walls and ceilings and don't match the rooms that they are attached to.

Repainting is easy so I let me kids pick out their own paint colors for their rooms and bathrooms, even if it's not what I would have picked. DS was nine when we did our reno and changed around his room. (He picked a pretty cool color brown/gold color, but I would have let him do whatever. DD picked very pink.) Here's a picture of our 'red room' which I had painted looong ago; it's the guest room in our basement. Yes, it's very red, but with furnishings etc the impact is lessened. Here's a shot of part of the kitchen, a BM color called 'Baked Clay'; has more orange and brown than a pure red (you can see it looks different in different light; the real color is somewhere between the two; ignore the weird reflections in 2nd pic): You mentioned he likes the Ravens; DS is a sports fan too and one of the cool things we got him is a 'ball claw' to hang a signed football (it's between the Bulls and Bears pennants.)

In Postwar houses with the same kind of evil, rough, sanded-plaster walls that we had when I was five, a chair rail may protect chairs' finish or upholstery from getting shredded, but generally, a chair rail's protection is intended to work the other way around: not to protect the chairs, but to keep the paint unmarked & the plaster un-gouged from the chairs being knocked into or dragged along the walls. I'm just sayin'. But chair rails protect the walls from more than chairs. There are also kids, and while plain walls with smooth finishes were all the style thing in 1965, they're also a lot harder to maintain in pristine condition than walls broken up into separate sections with moldings, which moldings allow you to freshen the walls without too much effort. In our family we had four boys & assorted pets, and in no house we ever lived did the place look as dingy & dodgy as our 196Os ranch with its long, narrow corridors of mint green & aqua & pink. Up above, the brand-new walls were immaculate, but from doorknob height on down, it was always a mess. Worse, because there was no convenient cut-off place--as there would have been with a chair rail--you couldn't just touch up the wall where a say, the heel of cowboy boot had gouged the plaster during a corridor ambush of the posse by a gang of bad guys, or where an errant Big Wheel had gone out of control & left a dirty scrape all the way down the hall. Add to those occasional incidents the continual finger-dragging that little kids seem to do by nature, and the the general grimy area that you get when you combine narrow halls & large dogs, and you can see the logic of having a molding a few feet above the floor. But our house was crisp & Modern and it didn't have what were considered superfluous, old-fashioned moldings, so it was either paint the whole wall, end-to-end, floor-to-ceiling, or do nothing & just leave the marks & smears & chipped plaster. My mother, being an early proponent of Energy Conservation, chose the latter, with the result that that place always looked like hell. When we moved into a big old Craftsman Style house, with a dark oak dado that stood chest high in the hall & the corridors, my mom no longer had to worry about telltale dirt & scuff marks on the walls. Not, of course, that she ever did. Anyway, stylistically speaking, chair rails may be out of place in a Modern house, but for simple practicality, they're hard to beat.