I built my own version of a Murphy bed at my 1st house. Sorry no pictures. It wasn't designed to hide or obscure the bed, rather make it storable to free up floor space for a workout area.
My design hinged at the headboard end. The pivot "mechanism" was a piece of 1-1/2 Sch 40 black pipe through the box frame and supported by angle iron legs, lagged to the floor. The pivot point was as close to the headboard as possible. There were additional foot board legs that rotated out (via gravity) to support the foot end of the bed. The top of the mattress was only about 15" off the floor making it a functional, albeit awkward guest bed.
I used a full size conventional mattress and no box spring. In hind sight, I should have used a foam mattress. I think it would have been more comfortable and a lot lighter weight (there were no counterbalance springs).
Rather than build an enclosure cabinet, I built two matching bookcases that flanked the headboard. These were about 16" deep with the width (about 42" wide) designed to fill the spaces between the bed (centered on the wall) and the two adjacent walls. When the bed was rotated into the stored position, I pinned it in place through the inboard side panels of the book cases.
The underside of the box frame (which was made using 3/4" veneer plywood) was trimmed out to not look like an afterthought, but it was obvious that it was a separate unit from the bookcases.
We left it at the house when we moved.