Remember that I had a plan for the mattress support? Here it is with the paper cloth torn off. Two of the boads were removed so I could saw this into a right and left door...I screwed the wood pieces back onto each door once I measured the size.
After that, I pulled out that free shower board and placed it along the bottom half of each door, then hid the seams with some tiny wood scrap and teeny nails. I caulked all the seams, front and back, and painted. The top halves were turned into windows the next day by pre-drilling some plexiglass and carefully screwing it in place--yes I cracked a corner somewhat!
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Lastly, here is a view with the doors hinged on.