Few more thoughts. Sorry the first ones may be unclear. You are stating your wanting two chairs and desk. The setup in my rv is that but it is 80" x 32" so we know that it is possible. What I ment that making the table/desk in the center down the 5" to make fit.
The platform looks hollow, so the wires could be relocated to take care of that issue. Have you taken the cover off to see the slide drive. Since there was a couch there they may have just made the cover that way not thinking of a lower profile. It is possible that the cover could be made lower or rounded to like a hump and leveling out the platform may not be needed. Carpeting over it could be doable or it could be used as a foot rest for the non reclining chair. You may have to take the top layer of the platform off to install some bracing because the couch was mounted on bracing and mounting the chairs may need some type to support for bolting.
My pullout table was part of my rv, with your rv the wall is straight where mine is curved. Recreating the unit with the pullout table and the pop up flat tv would be simple.
Chairs can be re upholstered to ones thoughts.
Sorry sometimes my mind works too much on improvements to items, I have two rv both elandans one is 1985 model that I had for past few years that I have working on, motor, transmission installing vortex 454 with 4l80e. And then other odds and ends. But just got the 89 model that PO took off parts to fix his, this one is in better shape and more items that I have been looking for. So now I am going to move some of the parts off the 85 to the 89. Project never stop.
Still like to chat to bounce ideas one projects.
Ps...understand on posting on something other than my computer, used wife's iPad and had long reply just to find out the lost connection after I sent and lost it all.